Package 'cops'

Title: Cluster Optimized Proximity Scaling
Description: Multidimensional scaling (MDS) methods that aim at pronouncing the clustered appearance of the configuration (Rusch, Mair & Hornik, 2021, <doi:10.1080/10618600.2020.1869027>). They achieve this by transforming proximities/distances with explicit power functions and penalizing the fitting criterion with a clusteredness index, the OPTICS Cordillera (Rusch, Hornik & Mair, 2018, <doi:10.1080/10618600.2017.1349664>). There are two variants: One for finding the configuration directly (COPS-C) for any Minkowski distance with given explicit power transformations and implicit ratio, interval and nonmetric optimal scaling transformations (Borg & Groenen, 2005, ISBN:978-0-387-28981-6), and one for using the augmented fitting criterion to find optimal hyperparameters for the explicit transformations (P-COPS). The package contains various functions, wrappers, methods and classes for fitting, plotting and displaying a large number of different MDS models (most of the functionality in smacofx) in the COPS framework. The package further contains a function for pattern search optimization, the ``Adaptive Luus-Jaakola Algorithm'' (Rusch, Mair & Hornik, 2021,<doi:10.1080/10618600.2020.1869027>) and a functions to calculate the phi-distances for count data or histograms.
Authors: Thomas Rusch [aut, cre] , Patrick Mair [aut] , Kurt Hornik [ctb]
Maintainer: Thomas Rusch <[email protected]>
License: GPL-2 | GPL-3
Version: 1.14-1
Built: 2024-11-21 05:52:33 UTC
Source: https://github.com/r-forge/stops

Help Index


Banking Crises Distances

Description

Matrix of Jaccard distances between 70 countries (Hungary and Greece were combined to be the same observation) based on their binary time series of having had a banking crises in a year from 1800 to 2010 or not. See data(bankingCrises) in package Ecdat for more info. The last column is Reinhart & Rogoffs classification as a low (3), middle- (2) or high-income country (1).

Format

A 69 x 70 matrix.

Source

data(bankingCrises) in library(Ecdat)


PCOPS version of approximated power stress model.

Description

This uses an approximation to power stress that makes use of smacofx as workhorse. Free parameters are kappa, lambda and nu

Usage

cop_apstress(
  dis,
  theta = c(1, 1, 1),
  type = "ratio",
  ndim = 2,
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  itmaxi = 1000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  normed = TRUE,
  scale = "sd"
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of parameters to optimize over. Must be of length three, with the first the kappa argument, the second the lambda argument and the third the nu argument. One cannot supply upsilon and tau as of yet. Defaults to 1 1 1.

type

MDS type.

ndim

number of dimensions of the target space

weightmat

(optional) a binary matrix of nonnegative weights.

init

(optional) initial configuration

itmaxi

number of iterations. default is 1000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

normed

should the cordillera be normed; defaults to TRUE

scale

should the configuration be scale adjusted

Value

A list with the components

  • stress: the stress-1 of the configuration

  • stress.m: default normalized stress (sqrt(stress-1))

  • copstress: the weighted loss value

  • OC: the OPTICS cordillera value

  • parameters: the theta parameters used for fitting (kappa, lambda, nu)

  • fit: the returned object of the fitting procedure (typically of class smacofB or smacofP)

  • cordillera: the cordillera object


PCOPS version of strain

Description

The free parameter that pcops optimizes over is lambda for power transformations of the observed proximities.

Usage

cop_cmdscale(
  dis,
  theta = 1,
  type = "ratio",
  weightmat = NULL,
  ndim = 2,
  init = NULL,
  itmaxi = 1000,
  add,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities.

type

MDS type. Ignored here.

weightmat

(optional) a matrix of nonnegative weights

ndim

number of dimensions of the target space

init

(optional) initial configuration

itmaxi

number of iterations. No effect here.

add

should the dissimilarities be made Euclidean? Defaults to TRUE.

...

additional arguments to be passed to the fitting procedure smacofx::cmdscale. Note we always use eig=TRUE and that can't be changed (we need the GOF). Also default if nothing is supplied is to use add=TRUE which in my opinion one always should to avoid negative eigenvalues.

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the corrdillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the badness-of-fit value (this isn't stress here but 1-(sum_ndim(max(eigenvalues,0))/sum_n(max(eigenvalues,0)), 1-GOF[2])

  • stress.m: default normalized stress (manually calculated)

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (lambda)

  • fit: the returned object of the fitting procedure, which is cmdscalex object with some extra slots for the parameters and stresses

  • cordillera: the cordillera object


PCOPS versions of elastic scaling models (via smacofSym)

Description

The free parameter is lambda for power transformations the observed proximities. The fitted distances power is internally fixed to 1 and the power for the weights=delta is -2. Allows for a weight matrix because of smacof.

Usage

cop_elastic(
  dis,
  theta = 1,
  type = "ratio",
  ndim = 2,
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  itmaxi = 1000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  normed = TRUE,
  scale = "sd"
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities. Defaults to 1.

type

MDS type.

ndim

number of dimensions of the target space

weightmat

(optional) a matrix of nonnegative weights (NOT the elscal weights)

init

(optional) initial configuration

itmaxi

number of iterations. default is 1000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the corrdillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

normed

should the cordillera be normed; defaults to TRUE

scale

should the configuration be scale adjusted

Value

A list with the components

  • stress: the stress-1

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (lambda)

  • fit: the returned object of the fitting procedure (plus a slot for the orginal data $deltaorig)

  • cordillera: the cordillera object


PCOPS version of elastic scaling with powers

Description

PCOPS version of elastic scaling with powers

Usage

cop_powerelastic(
  dis,
  theta = c(1, 1),
  type = "ratio",
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  ndim = 2,
  itmaxi = 10000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; a vector of length two where the first element is kappa (for the fitted distances), the second lambda (for the observed proximities). If a scalar for the free parameters is given it is recycled. Defaults to 1 1.

type

MDS type. Defaults to "ratio".

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

ndim

number of dimensions of the target space

itmaxi

number of iterations. default is 10000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress-1 value (sqrt(stress.m))

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the OPTICScordillera value

  • parameters: the parameters used for fitting (kappa, lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


PCOPS version of powermds

Description

This is power stress with free kappa and lambda but nu is internally fixed to 1, so no weight transformation.

Usage

cop_powermds(
  dis,
  theta = c(1, 1),
  type = "ratio",
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  ndim = 2,
  itmaxi = 10000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; a vector of length 2 where the first element is kappa (for the fitted distances), the second lambda (for the observed proximities). If a scalar is given it is recycled. Defaults to 1,1.

type

MDS type. Defaults to ratio.

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

ndim

number of dimensions of the target space

itmaxi

number of iterations. default is 10000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress-1 value

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (kappa, lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


PCOPS version of sammon with powers

Description

This is power stress with free kappa and lambda but nu is fixed to -1 and the weights are delta.

Usage

cop_powersammon(
  dis,
  theta = c(1, 1),
  type = "ratio",
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  ndim = 2,
  itmaxi = 10000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; a vector of length two where the first element is kappa (for the fitted distances), the second lambda (for the observed proximities). If a scalar is given it is recycled for the free parameters. Defaults to 1 1.

type

MDS type. defaults to ratio.

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

ndim

number of dimensions of the target space

itmaxi

number of iterations (of powerstress). default is 10000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress1 value (sqrt(stress.m))

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the explicit parameters used for fitting (kappa, lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


COPS version of powerstress

Description

Power stress with free kappa and lambda and rho (the theta argument) and ratio and interval optimal scaling.

Usage

cop_powerstress(
  dis,
  theta = c(1, 1, 1),
  type = "ratio",
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  ndim = 2,
  itmaxi = 10000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; the first is kappa (for the fitted distances), the second lambda (for the observed proximities), the third nu (for the weights). If a scalar is given it is recycled. Defaults to 1 1 1.

type

MDS type. Default is ratio.

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

ndim

number of dimensions of the target space

itmaxi

number of iterations. default is 10000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (kappa, lambda, nu)

  • fit: the returned object of the fitting procedure plus a slot for the original data $deltaorig

  • cordillera: the cordillera object


PCOPS version of restricted powerstress.

Description

This is a power stress where kappa and lambda are free to vary but restricted to be equal, so the same exponent will be used for distances and dissimilarities. nu (for the weights) is also free.

Usage

cop_rpowerstress(
  dis,
  theta = c(1, 1, 1),
  type = "ratio",
  weightmat = NULL,
  init = NULL,
  ndim = 2,
  itmaxi = 10000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; the first two arguments are for kappa and lambda and should be equal (for the fitted distances and observed proximities), the third nu (for the weights). Internally the kappa and lambda are equated based on theta[1]. If a scalar is given it is recycled (so all elements of theta are equal); if a vector of length 2 is given, it gets expanded to c(theta[1],theta[1],theta[2]). Defaults to 1 1 1.

type

MDS type. Defaults to "ratio".

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

ndim

number of dimensions of the target space

itmaxi

number of iterations. default is 10000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress1 value (sqrt(stress.m))

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the explicit parameters used for fitting (kappa=lambda, nu)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


PCOPS version of rstress

Description

Free parameter is kappa=2r for the fitted distances.

Usage

cop_rstress(
  dis,
  theta = 1,
  type = "ratio",
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  ndim = 2,
  itmaxi = 10000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; this must be a scalar of the kappa=2*r transformation for the fitted distances proximities. Defaults to 1. Note that what is returned is r, not kappa.

type

MDS type. Defaults to "ratio".

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

ndim

number of dimensions of the target space

itmaxi

number of iterations. default is 10000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress-1 value

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (r)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


PCOPS version of Sammon mapping from MASS

Description

Uses smacofx::sammon wrapper for MASS::sammon. The free parameter is lambda for power transformations of the observed proximities.

Usage

cop_sammon(
  dis,
  theta = 1,
  type = "ratio",
  ndim = 2,
  init = NULL,
  weightmat = NULL,
  itmaxi = 1000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities. Defaults to 1.

type

MDS type. Only "ratio" here.

ndim

number of dimensions of the target space

init

(optional) initial configuration

weightmat

(optional) a matrix of nonnegative weights.

itmaxi

number of iterations. Default is 1000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the corrdillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

if TRUE the configuration is scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress-1

  • stress.m: default normalized stress (stress-1^2)

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (lambda)

  • fit: the returned object of the fitting procedure smacofx::sammon

  • cordillera: the cordillera object


Another COPS versions of Sammon mapping models (via smacofSym)

Description

Uses smacofSym, so it can deal with a weightmatrix and different types. The free parameter is lambda for power transformations of the observed proximities.

Usage

cop_sammon2(
  dis,
  theta = 1,
  type = "ratio",
  ndim = 2,
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  itmaxi = 1000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  normed = TRUE,
  scale = "sd"
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

theta the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities. Defaults to 1.

type

MDS type. Default is ratio.

ndim

number of dimensions of the target space

weightmat

(optional) a matrix of nonnegative weights (NOT the sammon weights)

init

(optional) initial configuration

itmaxi

number of iterations. default is 1000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the corrdillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

normed

should the cordillera be normed; defaults to TRUE

scale

should the configuration be scale adjusted

Value

A list with the components

  • stress: the stress-1 value

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


PCOPS versions of smacofSphere models

Description

The free parameter is lambda for power transformations the observed proximities. The fitted distances power is internally fixed to 1 and the power for the weights is 1.

Usage

cop_smacofSphere(
  dis,
  theta = 1,
  type = "ratio",
  ndim = 2,
  weightmat = NULL,
  init = NULL,
  itmaxi = 5000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  normed = TRUE,
  scale = "sd",
  stresstype = "default"
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities. Defaults to 1.

type

MDS type

ndim

number of dimensions of the target space

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

itmaxi

number of iterations. default is 1000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the corrdillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

normed

should the cordillera be normed; defaults to TRUE

scale

should the configuration be scale adjusted

stresstype

which stress to report. Only takes smacofs default stress currrently.

Value

A list with the components

  • stress: the stress-1 value

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


PCOPS versions of smacofSym models

Description

The free parameter is lambda for power transformations the observed proximities. The fitted distances power is internally fixed to 1 and the power for the weights is 1.

Usage

cop_smacofSym(
  dis,
  theta = 1,
  type = "ratio",
  ndim = 2,
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  itmaxi = 1000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  normed = TRUE,
  scale = "sd",
  stresstype = "default"
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector; should be a scalar for the lambda (proximity) transformation. Defaults to 1.

type

MDS type.

ndim

number of dimensions of the target space

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

itmaxi

number of iterations. default is 1000

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

normed

should the cordillera be normed; defaults to TRUE

scale

should the configuration be scale adjusted

stresstype

which stress to report. Only takes smacofs default stress currrently.

Value

A list with the components

  • stress: the stress

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


PCOPS version of sstress

Description

Free parameter is lambda for the observed proximities. Fitted distances are transformed with power 2, weights have exponent of 1. Note that the lambda here works as a multiplicator of 2 (as sstress has f(delta^2)).

Usage

cop_sstress(
  dis,
  theta = 1,
  type = "ratio",
  weightmat = 1 - diag(nrow(dis)),
  init = NULL,
  ndim = 2,
  itmaxi = 10000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  scale = "sd",
  normed = TRUE
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities. Defaults to 1. Note that the lambda here works as a multiplicator of 2 (as sstress has f(delta^2)).

type

MDS type, defaults to "ratio".

weightmat

(optional) a matrix of nonnegative weights

init

(optional) initial configuration

ndim

number of dimensions of the target space

itmaxi

number of iterations. default is 10000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

scale

should the configuration be scale adjusted

normed

should the cordillera be normed; defaults to TRUE

Value

A list with the components

  • stress: the stress-1 value

  • stress.m: default normalized stress

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object


High Level COPS Function

Description

About the function cops: The high level function allows for minimizing copstress for a clustered MDS configuration. Allows to choose COPS-C (finding a configuration from copstress with cordillera penalty) and profile COPS (finding hyperparameters for MDS models with power transformations). It is a wrapper for copstressMin and pcops.

Usage

cops(
  dis,
  variant = c("1", "2", "Variant1", "Variant2", "v1", "v2", "COPS-C", "P-COPS",
    "configuration-c", "profile", "copstress-c", "p-copstress", "COPS-P", "copstress-p",
    "cops-c", "p-cops", "copsc", "pcops"),
  ...
)

Arguments

dis

a dissimilarity matrix or a dist object

variant

a character string specifying which variant of COPS to fit. Allowed is any of the following "1","2","Variant1","Variant2","v1","v2","COPS-C","P-COPS","configuration-c","profile","copstress-c","p-copstress". Defaults to "COPS-C".

...

arguments to be passed to copstressMin (for Variant 1) or pcops (for Variant 2).

Value

For COPS-C Variant 1 see copstressMin, for P-COPS Variant 2 see pcops

Examples

dis<-as.matrix(smacof::kinshipdelta)

#COPS-C with equal weight to stress and cordillera 
res1<-cops(dis,variant="COPS-C",stressweight=0.75,cordweight=0.25,
          minpts=2,itmax=1000) #use higher itmax in real
res1
summary(res1)
plot(res1)
plot(res1,"reachplot")



#s-stress type copstress (i.e. kappa=2, lambda=2)
res3<-cops(dis,variant="COPS-C",kappa=2,lambda=2,stressweight=0.5,cordweight=0.5) 
res3
summary(res3)
plot(res3)


# power-stress type profile copstress
# search for optimal kappa and lambda between
# kappa=0.5,lambda=0.5 and kappa=2,lambda=5
# nu is fixed on -1
ws<-1/dis
diag(ws)<-1 
res5<-cops(dis,variant="P-COPS",loss="powerstress",
          theta=c(1.4,3,-1), lower=c(1,0.5,-1),upper=c(3,5,-1),
          weightmat=ws, stressweight=0.9,cordweight=0.1) 
res5
summary(res5)
plot(res5)

Calculates copstress for given MDS object

Description

Calculates copstress for given MDS object

Usage

copstress(
  obj,
  stressweight = 1,
  cordweight = 5,
  q = 1,
  minpts = 2,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  normed = TRUE,
  scale = c("std", "sd", "proc", "none"),
  init,
  ...
)

Arguments

obj

MDS object (supported are sammon, cmdscale, smacof, rstress, powermds)

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to 2

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is very verbose (copstress level), >3 is extremely (up to MDS optimization level)

normed

should the cordillera be normed; defaults to TRUE

scale

should the configuration be scale adjusted.

init

a reference configuration when doing procrustes adjustment

...

additional arguments to be passed to the cordillera function

Value

A list with the components

  • copstress: the weighted loss value

  • OC: the Optics cordillera value

  • parameters: the parameters used for fitting (kappa, lambda)

  • cordillera: the cordillera object


Fitting a COPS-C Model (COPS Variant 1).

Description

Minimizing Copstress to obtain a clustered ratio, interval, spline or ordinal PS configuration with given explicit power transformations theta. The function allows mix-and-match of explicit (via theta) and implicit (via type) transformations by setting the kappa, lambda, nu (or theta) and type arguments. This function also supports fitting any Minkowski distance in the configuration.

Usage

copstressMin(
  delta,
  kappa = 1,
  lambda = 1,
  nu = 1,
  theta = c(kappa, lambda, nu),
  type = c("ratio", "interval", "ordinal"),
  ties = "primary",
  weightmat = 1 - diag(nrow(delta)),
  ndim = 2,
  init = NULL,
  stressweight = 0.975,
  cordweight = 0.025,
  q = 1,
  minpts = ndim + 1,
  epsilon = max(10, max(delta)),
  dmax = NULL,
  rang,
  optimmethod = c("NelderMead", "Newuoa", "BFGS", "SANN", "hjk", "solnl", "solnp",
    "subplex", "snomadr", "hjk-Newuoa", "hjk-BFGS", "BFGS-hjk", "Newuoa-hjk", "cmaes",
    "direct", "direct-Newuoa", "direct-BFGS", "genoud", "gensa"),
  verbose = 0,
  scale = c("sd", "rmsq", "proc", "none"),
  normed = TRUE,
  accuracy = 1e-07,
  itmax = 10000,
  stresstype = c("stress-1", "stress"),
  principal = FALSE,
  minkp = 2,
  spline.degree = 2,
  spline.intKnots = 2,
  ...
)

copsc(
  delta,
  kappa = 1,
  lambda = 1,
  nu = 1,
  theta = c(kappa, lambda, nu),
  type = c("ratio", "interval", "ordinal"),
  ties = "primary",
  weightmat = 1 - diag(nrow(delta)),
  ndim = 2,
  init = NULL,
  stressweight = 0.975,
  cordweight = 0.025,
  q = 1,
  minpts = ndim + 1,
  epsilon = max(10, max(delta)),
  dmax = NULL,
  rang,
  optimmethod = c("NelderMead", "Newuoa", "BFGS", "SANN", "hjk", "solnl", "solnp",
    "subplex", "snomadr", "hjk-Newuoa", "hjk-BFGS", "BFGS-hjk", "Newuoa-hjk", "cmaes",
    "direct", "direct-Newuoa", "direct-BFGS", "genoud", "gensa"),
  verbose = 0,
  scale = c("sd", "rmsq", "proc", "none"),
  normed = TRUE,
  accuracy = 1e-07,
  itmax = 10000,
  stresstype = c("stress-1", "stress"),
  principal = FALSE,
  minkp = 2,
  spline.degree = 2,
  spline.intKnots = 2,
  ...
)

copStressMin(
  delta,
  kappa = 1,
  lambda = 1,
  nu = 1,
  theta = c(kappa, lambda, nu),
  type = c("ratio", "interval", "ordinal"),
  ties = "primary",
  weightmat = 1 - diag(nrow(delta)),
  ndim = 2,
  init = NULL,
  stressweight = 0.975,
  cordweight = 0.025,
  q = 1,
  minpts = ndim + 1,
  epsilon = max(10, max(delta)),
  dmax = NULL,
  rang,
  optimmethod = c("NelderMead", "Newuoa", "BFGS", "SANN", "hjk", "solnl", "solnp",
    "subplex", "snomadr", "hjk-Newuoa", "hjk-BFGS", "BFGS-hjk", "Newuoa-hjk", "cmaes",
    "direct", "direct-Newuoa", "direct-BFGS", "genoud", "gensa"),
  verbose = 0,
  scale = c("sd", "rmsq", "proc", "none"),
  normed = TRUE,
  accuracy = 1e-07,
  itmax = 10000,
  stresstype = c("stress-1", "stress"),
  principal = FALSE,
  minkp = 2,
  spline.degree = 2,
  spline.intKnots = 2,
  ...
)

Arguments

delta

numeric matrix or dist object of a matrix of proximities

kappa

power transformation for fitted distances

lambda

power transformation for proximities (only used if type="ratio" or "interval")

nu

power transformation for weights

theta

the theta vector of powers; the first is kappa (for the fitted distances if it exists), the second lambda (for the observed proximities if it exist and type="ratio" or "interval"), the third is nu (for the weights if it exists). If less than three elements are is given as argument, it will be recycled. Defaults to 1 1 1. Will override any kappa, lambda, nu parameters if they are given and do not match.

type

what type of MDS to fit. Currently one of "ratio", "interval" or "ordinal". Default is "ratio".

ties

the handling of ties for ordinal (nonmetric) MDS. Possible are "primary" (default), "secondary" or "tertiary".

weightmat

(optional) a matrix of nonnegative weights; defaults to 1 for all off diagonals

ndim

number of dimensions of the target space

init

(optional) initial configuration

stressweight

weight to be used for the fit measure; defaults to 0.975

cordweight

weight to be used for the cordillera; defaults to 0.025

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS, see optics where it is called minPts; defaults to ndim+1.

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked, see optics; defaults to 10 (which is plenty for the explicit normalization we use). Note this means we do not expect any noise objects per default. This number will rarely be exceeded if we standardize the configuration as is the default in cops. However if no standardization is applied or there is a procrustes adjustment to a configuration with variance of 10 or more on any of the axes, it can have the effect of being too small. In that case just set a much higher epsilon.

dmax

The winsorization limit of reachability distances in the OPTICS Cordillera. If supplied, it should be either a numeric value that matches 'max(rang)' or 'NULL'; if 'NULL' it is found as 1.5 times (for kappa >1) or 1 times (for kappa <=1) the maximum reachbility value of the power torgerson model with the same lambda. If 'dmax' and 'rang' are supplied and 'dmax' is not 'max(rang)', a warning is given and 'rang' takes precedence.

rang

range of the reachabilities to be considered. If missing it is found from the initial configuration by taking 0 as the lower boundary and dmax (see above) as upper boundary. See also cordillera

optimmethod

What optimizer to use? Choose one string of 'Newuoa' (newuoa), 'NelderMead' (see optim), 'hjk' (Hooke-Jeeves algorithm from hjk), 'solnl' (from solnl), 'solnp' (from solnp), 'subplex' (from subplex), 'SANN' (simulated annealing, optim), 'BFGS' (see optim), 'snomadr' (from snomadr), 'genoud' (from genoud), 'gensa' (from GenSA), 'cmaes' (from cma_es) and 'direct' (from direct). See the linked functions for details on these solvers. There are also combinations that proved to work well good, like 'hjk-Newuoa', 'hjk-BFGS', 'BFGS-hjk', 'Newuoa-hjk', 'direct-Newuoa' and 'direct-BFGS'. Usually everything with 'hjk', 'BFGS', 'Newuoa', 'subplex' and 'solnl' in it work rather well in an acceptable time frame (depending on the smoothness of copstress). Default is 'hjk-Newuoa'.

verbose

numeric value hat prints information on the fitting process; >2 is very verbose

scale

Scale the configuration (in MDS stress is invariant up to a scaling factor). One of "none" (so no extra scaling of the configuration but normalized to sum delta^2=1), "sd" (configuration divided by the highest standard deviation of any the columns), "proc" (procrustes adjustment to the initial fit) and "rmsq" (configuration divided by the maximum root mean square of the columns). Default is "sd" which often gives a nicer spread on the axes. Note that the scaled configuration is returned as $conf and the unscaled as $usconf, so manual calculation of the OC should be done with $conf.

normed

should the Cordillera be normed; defaults to TRUE.

accuracy

numerical accuracy, defaults to 1e-7.

itmax

maximum number of iterations. Defaults to 10000. For the two-step algorithms if itmax is exceeded by the first solver, the second algorithm is run for at least 0.1*itmax (so overall itmax may be exceeded by a factor of 1.1).

stresstype

which stress to use in the copstress. Defaults to stress-1. If anything else is set, explicitly normed stress which is (stress-1)^2 is used. Using stress-1 puts more weight on MDS fit.

principal

If ‘TRUE’, principal axis transformation is applied to the final configuration.

minkp

Power of the Minkowski distance. Defaults to 2 (Euclidean distance).

spline.degree

Degree of the spline for ‘mspline’ MDS type

spline.intKnots

Number of interior knots of the spline for ‘mspline’ MDS type

...

additional arguments to be passed to the optimization procedure

Details

This is an extremely flexible approach to least squares proximity scaling: It supports ratio power stress; ratio, interval and ordinal r stress and ratio, interval and ordinal MDS with or without a COPS penalty. Famous special cases of these models that can be fitted are multiscale MDS if kappa->0 and delta=log(delta), Alscal MDS (sstress) with lambda=kappa=2, sammon type mapping with weightmat=delta and nu=-1, elastic scaling with weightmat=delta and nu=-2. Due to mix-and-match this function also allows to fit models that have not yet been published, such as for example an "elastic scaling ordinal s-stress with cops penalty".

If one wants to fit these models without the cops penalty, we recommend to use powerStressMin (for ratio and interval MDS with any power transformation for weights, dissimilarities and distances) or rStressMin (for ratio, interval and ordinal MDS with power transformations for distances and weights) as these use majorization.

Some optimizers (including the default hjk-Newuoa) will print a warning if itmax is (too) small or if there was no convergence. Consider increasing itmax then.

For some solvers there sometimes may be an error [NA/NaN/Inf in foreign function call (arg 3)] stemming from smacof::transform(). This happens when the algorithm places two object at exactly the same place so their fitted distance is 0. This is good from an OPTICS Cordillera point of view (as it is more clustered) which is why some solvers like to pick that up, but it can lead to an issue in the optimal scaling in smacof. This can usually be mitigated when specifying the model by either using less cordweight, less itmax, less accuracy or combining the two offending objects into one (so include them as a combined row in the distance matrix).

We might eventually switch to newuoa in nloptr.

Value

A copsc object (inheriting from smacofP). A list with the components

  • delta: the original untransformed dissimilarities

  • tdelta: the explicitly transformed dissimilarities

  • dhat: the explicitly transformed dissimilarities (dhats), optimally scaled and normalized (which are approximated by the fit)

  • confdist: Configuration distances, the transformed fitted distances

  • conf: the configuration (normed) and scaled as specified in scale.

  • usconf: the unscaled configuration (normed to sum delta^2=1). Scaling applied to usconf gives conf.

  • parameters, par, pars : the theta vector of powers tranformations (kappa, lambda, nu)

  • niter: number of iterations of the optimizer.

  • stress: the square root of explicitly normalized stress (calculated for confo).

  • spp: stress per point

  • ndim: number of dimensions

  • model: Fitted model name

  • call: the call

  • nobj: the number of objects

  • type, loss, losstype: stresstype

  • stress.m: The stress used for copstress. If stresstype="stress-1" this is like $stress else it is stress^2

  • copstress: the copstress loss value

  • resmat: the matrix of residuals

  • weightmat: the matrix of untransformed weights

  • tweightmat: the transformed weighting matrix (here weightmat^nu)

  • OC: the (normed) OPTICS Cordillera object (calculated for scaled conf)

  • OCv: the (normed) OPTICS Cordillera value alone (calculated for scaled conf)

  • optim: the object returned from the optimization procedure

  • stressweight, cordweight: the weights of the stress and OC respectively (v_1 and v_2)

  • optimmethod: The solver used

  • type: the type of MDS fitted

  • minkowski: the power of the minkowski distance fitted in the configuration.

Examples

dis<-as.matrix(smacof::kinshipdelta)

set.seed(1)
## Copstress with equal weight to stress and cordillera and L2 configuration distance
res1<-copstressMin(dis,stressweight=0.75,cordweight=0.25,
                  itmax=100) #use higher itmax about 10000 
res1
summary(res1)
plot(res1)  #super clustered 

## Copstress with equal weight to stress and cordillera and L1 configuration distance 
res2<-copstressMin(dis,stressweight=0.75,cordweight=0.25,
                  itmax=100, minkp=1) #use higher itmax about 10000
res2
plot(res2)

##Alias name 
res1<-copsc(dis,stressweight=0.75,
                  cordweight=0.25,itmax=100) 


## Elastic scaling mspline s-stress in L1 with cops penalty
res3<-copsc(dis,type="mspline",kappa=2,nu=-2,weightmat=dis,
            stressweight=0.5, cordweight=0.5,itmax=100)

Double centering of a matrix

Description

Double centering of a matrix

Usage

doubleCenter(x)

Arguments

x

numeric matrix

Value

the double centered matrix


Explicit Normalization Normalizes distances

Description

Explicit Normalization Normalizes distances

Usage

enorm(x, w = 1)

Arguments

x

numeric matrix

w

weight

Value

a constant


(Adaptive) Version of Luus-Jakola Optimization

Description

Adaptive means that the search space reduction factors in the number of iterations; makes convergence faster at about 100 iterations

Usage

ljoptim(
  x,
  fun,
  ...,
  red = ifelse(adaptive, 0.99, 0.95),
  lower,
  upper,
  acc = 1e-06,
  accd = 1e-04,
  itmax = 1000,
  verbose = 0,
  adaptive = TRUE
)

Arguments

x

optional starting values

fun

function to minimize

...

additional arguments to be passed to the function to be optimized

red

value of the reduction of the search region

lower

The lower contraints of the search region

upper

The upper contraints of the search region

acc

if the numerical accuracy of two successive target function values is below this, stop the optimization; defaults to 1e-6

accd

if the width of the search space is below this, stop the optimization; defaults to 1e-4

itmax

maximum number of iterations

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

adaptive

should the adaptive version be used? defaults to TRUE.

Value

A list with the components (see also optim)

  • par The position of the optimimum in the search space (parameters that minimize the function; argmin fun)

  • value The value of the objective function at the optimum (min fun)

  • counts The number of iterations performed at convergence with entries fnction for the number of iterations and gradient which is always NA at the moment

  • convergence 0 successful completion by the accd or acc criterion, 1 indicate iteration limit was reached, 99 is a problem

  • message is NULL (only for compatibility or future use)

Examples

fbana <- function(x) {
x1 <- x[1]
x2 <- x[2]
100 * (x2 - x1 * x1)^2 + (1 - x1)^2
}
res1<-ljoptim(c(-1.2,1),fbana,lower=-5,upper=5,accd=1e-16,acc=1e-16)
res1

set.seed(210485)
fwild <- function (x) 10*sin(0.3*x)*sin(1.3*x^2) + 0.00001*x^4 + 0.2*x+80
plot(fwild, -50, 50, n = 1000, main = "ljoptim() minimising 'wild function'")
res2<-ljoptim(50, fwild,lower=-50,upper=50,adaptive=FALSE,accd=1e-16,acc=1e-16)
points(res2$par,res2$value,col="red",pch=19)
res2

Distances of MATCH-ADTC modules

Description

A symmetric distance matrix of 32 MATCH-ADT modules based on their usage by clinicians. The raw data were counts of how often each module has been used with each of 449 youths, resulting in a count profile of each module. Based on that the phi-distance between the modules has been calculated.

Format

A 32 x 32 distance matrix.

Details

This is an object that inherits from class distance (see package analogue) and matrix.


Auxfunction1

Description

only used internally

Usage

mkBmat(x)

Arguments

x

matrix


Take matrix to a power

Description

Take matrix to a power

Usage

mkPower(x, r)

Arguments

x

matrix

r

numeric (power)

Value

a matrix


Profile COPS Function (aka COPS Variant 2)

Description

Metaparameter selection for MDS models baseed on the Profile COPS approach (COPS Variant 2). It uses copstress for hyperparameter selection of explicit transformations (currently power transformations). It is a special case of a STOPS model and predated it; stops has more functionality and can be seen as the successor. pcops uses explicitly normalized stress for copstress (not stress-1).

Usage

pcops(
  dis,
  loss = c("stress", "smacofSym", "smacofSphere", "strain", "sammon", "rstress",
    "powermds", "sstress", "elastic", "powersammon", "powerelastic", "powerstress",
    "sammon2", "powerstrain", "apstress", "rpowerstress"),
  type = "ratio",
  weightmat = NULL,
  ndim = 2,
  init = NULL,
  theta = c(1, 1, 1),
  stressweight = 1,
  cordweight,
  q = 2,
  minpts = ndim + 1,
  epsilon = 100,
  rang,
  optimmethod = c("ALJ", "pso", "SANN", "direct", "directL", "stogo", "MADS", "hjk"),
  lower = 0.5,
  upper = 5,
  verbose = 0,
  scale = c("proc", "sd", "none", "std"),
  normed = TRUE,
  s = 4,
  acc = 1e-05,
  itmaxo = 200,
  itmaxi = 5000,
  ...
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

loss

which loss function to be used for fitting, defaults to strain. See Details.

type

MDS type which may be one of "ratio", interval", "ordinal". Defaults to "ratio". Note not all loss arguments support all types; if not there will be an error and infor which types are supported. In that case choose another type.

weightmat

(optional) a matrix of nonnegative weights; defaults to 1 for all off diagonals

ndim

number of dimensions of the target space

init

(optional) initial configuration. If not supplied, the Torgerson scaling result of the dissimilarity matrix dis^theta[2]/enorm(dis^theta[2],weightmat) is used.

theta

the theta vector of free parameters; see details for the number of free parameters for each loss function. Defaults to 1 for all free parameters. Make sure to supply a theta of the correct length as the mechanisms in place to automatically choose theta/upper/lower are dependent on the optimizer and ad hoc: If this is a vector with more elements than necessary, it is either cut (so for a vector of length 3 and a function with 2 free parameters, the first two elements of the vector are used) or there will be an error. If a scalar is given as argument and the number of free parameters is larger than 1, the scalar will be recycled and this may also make the optimizers equate all free parameters.

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; if missing gets estimated from the initial configuration so that copstress = 0 for theta=1

q

the norm of the cordillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the minimum reachabilities to be considered. If missing it is found from the initial configuration by taking 1.5 times the maximal minimum reachability of the model with theta=1. If NULL it will be normed to each configuration's minimum and maximum distance, so an absolute value of goodness-of-clusteredness. Note that the latter is not necessarily desirable when comparing configurations for their relative clusteredness. See also cordillera.

optimmethod

What general purpose optimizer to use? Defaults to our adaptive LJ version (ALJ). Also allows particle swarm optimization with s particles ("pso", psoptim) and simulated annealing ("SANN", optim), "directT" or "directL" (see direct), Hooke-Jeeves ("hjk", hjk), StoGo ("stogo", stogo), and "snomadr" (snomadr). We recommend not using SANN and pso with the rstress, sstress and the power stress models. We made good experiences with ALJ, stogo, direct and directL and also snomadr.

lower

A vector of the lower box contraints of the search region. Its length must match the length of theta.

upper

A vector of the upper box contraints of the search region. Its length must match the length of theta.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose. Note that for models with some parameters fixed, the iteration progress of the optimizer shows different values also for the fixed parameters because due to the modular setup we always optimize over a three parameter vector. These values are inconsequential however as internally they will be fixed.

scale

should the configuration be scaled and/or centered for calculating the cordillera? "std" standardizes each column of the configurations to mean=0 and sd=1 (typically not a good idea), "sd" scales the configuration by the maximum standard devation of any column (default), "proc" adjusts the fitted configuration to the init configuration (or the Togerson scaling solution if init=NULL). This parameter only has an effect for calculating the cordillera, the fitted and returned configuration is NOT scaled.

normed

should the cordillera be normed; defaults to TRUE

s

number of particles if pso is used

acc

termination threshold difference of two successive outer minimization steps.

itmaxo

iterations of the outer step (optimization over the hyperparmeters; if solver allows it). Defaults to 200.

itmaxi

iterations of the inner step (optimization of the MDS). Defaults to 5000.

...

additional arguments to be passed to the optimization procedure

Details

Currently allows for the following models:

  • Power transformations applied to observed proximities only (theta, upper, lower should be numeric scalar): Strain loss/Torgerson scaling (strain, workhorse: smacofx::cmdscale), Stress for symmetric matrices (smacofSym, stress,smacofSphere for scaling onto a sphere; workhorse: smacof::smacofSym), Sammon mapping (sammon, workhorse is smacofx::sammon or sammon2, workhorse: smacof::smacofSym), elastic scaling (elastic, workhorse smacof::smacofSym), Alscal or S-Stress sstress (workhorse: smacofx::powerStressMin)

  • Power transformations of fitted distances only (theta, upper, lower should be numeric scalar): r-stress rstress (workhorse: smacofx:rStressMin)

  • Power transformations applied to fitted distances and observed proximities (theta, upper, lower should be numeric of length 2): Power MDS (powermds, workhorse: smacofx::powerStressMin), Sammon Mapping/elastic scaling with powers (powersammon, powerelastic, workhorse: smacofx::powerStressMin)

  • Power transformations applied to fitted distances, observed proximities and weights (theta, upper, lower should be numeric of length 3): power stress (POST-MDS, powerstress, workhorse: smacofx::powerStressMin), restricted power stress with equal transformations for distances and proximities (rpowerstress); workhorse: smacofx::powerStressMin), approximated power stress (apstress; workhorse: smacof::smacofSym)

Value

A list with the components

  • copstress: the weighted loss value

  • OC: the OPTICS cordillera for the scaled configuration (as defined by scale)

  • optim: the object returned from the optimization procedure

  • stress: the stress (square root of stress.m)

  • stress.m: default normalized stress

  • parameters: the parameters used for fitting (kappa, lambda)

  • fit: the returned object of the fitting procedure

  • cordillera: the cordillera object

Examples

dis<-as.matrix(smacof::kinshipdelta)
set.seed(210485)
#configuration is scaled with highest column sd for calculating cordilera 
res1<-pcops(dis,loss="strain",lower=0.1,upper=5,minpts=2) 
res1
summary(res1)
plot(res1)

Squared p-distances

Description

Squared p-distances

Usage

pdist(x, p)

Arguments

x

numeric matrix

p

p>0 the Minkoswki distance

Value

squared Minkowski distance matrix


Calculating the pairwise phi distance matrix between n vectors

Description

The pairwise phi-distance of two vectors x and y is sqrt(sum(((x[i]-y[i])^2)/((x[i]+y[i])*(sum(x)+sum(y))))). The function calculates this for all pairs of rows of a matrix or data frame X.

Usage

phidistance(X)

Arguments

X

an n times p numeric matrix or data frame

Value

a symmetric n times n matrix of pairwise phi distance (between rows of X) with 0 in the main diagonal. Is an object of class distance and matrix.


S3 plot method for p-cops objects

Description

S3 plot method for p-cops objects

Usage

## S3 method for class 'pcops'
plot(x, plot.type, main, asp = 1, ...)

Arguments

x

an object of class cops

plot.type

String indicating which type of plot to be produced: can be one of "confplot", "reachplot", "resplot", "transplot", "Shepard", "stressplot", "bubbleplot", "histogram" *see plot.smacofP, plot.smacofB and plot.copsc). Note that not all plots might be available for all losses.

main

the main title of the plot

asp

aspect ratio of x/y axis; defaults to 1; setting to 1 will lead to an accurate represenation of the fitted distances.

...

Further plot arguments passed: see 'plot.smacofP', 'plot.smacofB' and 'plot' for detailed information.

Details

See plot.smacofP

#@importFrom smacofx plot

Examples

dis<-as.matrix(smacof::kinshipdelta)
resl<-pcops(dis,loss="stress",lower=0.1,upper=5,minpts=2)
plot(resl,plot.type="confplot")
plot(resl,plot.type="reachplot")
plot(resl,plot.type="Shepard")
plot(resl,plot.type="transplot")
plot(resl,plot.type="stressplot")
plot(resl,plot.type="bubbleplot")
plot(resl,plot.type="histogram")

procruster: a procrustes function

Description

procruster: a procrustes function

Usage

procruster(x)

Arguments

x

numeric matrix

Value

a matrix


Secular Equation

Description

Secular Equation

Usage

secularEq(a, b)

Arguments

a

matrix

b

matrix


Squared distances

Description

Squared distances

Usage

sqdist(x)

Arguments

x

numeric matrix

Value

squared distance matrix