Analysis of free sorting data.

Description

This package gives several tools for analysing free sorting data.

Details

The function for managing sorting data is SortingPartition().Function for computing consensus partition is ConsensusPartition(). Multidimensional scaling of sorting data may be performed with the function MdsSort().

Author(s)

Philippe Courcoux

Maintainer: <philippe.courcoux@oniris-nantes.fr>

References

Ph. Courcoux, P. Faye, E.M. Qannari (2014) Determination of the consensus partition and cluster analysis of subjects in a free sorting task experiment. Food Quality and Preference, 32, 107-112.

See Also

SortingPartition, ConsensusPartition, MdsSort

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  res<-ConsensusPartition(Aroma)
  DescriptionPartition(res$Consensus)
  resMds<-MdsSort(Aroma,ndim=3)
  plotMds(resMds)

Aroma sorting data

Description

Partitions of 16 aromas by 31 subjects (free sorting task)

Usage

data(AromaSort)

Format

A data frame with 16 observations (aromas) and 31 variables (subjects).

Details

List of stimuli : Lemon, Grapefruit, Pineapple, Pear, Honey, Butter, Grilledbread, Grilledhazelnut, Strawberry, Raspberry, Cherry, Blackcurrant, Greenpepper, Smoked, Pepper, Licorice.

References

Ph. Courcoux, P. Faye, E.M. Qannari (2014) Determination of the consensus partition and cluster analysis of subjects in a free sorting task experiment. Food Quality and Preference 32, 107-112

Examples

data(AromaSort)

Aroma data (verbalisation by 31 subjects)

Description

Free sorting of 16 aromas described by 31 subjects. Data are occurences of terms for describing stimuli. Partitions given by the subjects are described in the AromaSort data.

Usage

data(AromaTerms)

Format

A data frame with 16 observations (aromas) and 36 variables (terms). Rownames and colnames refer to stimuli and terms labels.

Details

List of terms : Acid, Smoked ,Heady, Citrus, Lemon, Cake, Milk, Woody, Grain, Low, Redfruit, Grilled, Strong, Fat, Vegetal, Medicine, Chemical, Licorice, Bread, Alcohol, Almond, Caramel, Coal, Unpleasant, Soft, Pepper, Flower, Fresh, Red, Fruit, Natural, Spicy, Sugar, Hot, Pleasant, Candy.

Examples

data(AromaTerms)

Consensus of Partitions

Description

Returns the consensus partition among a set of partitions

Usage

ConsensusPartition(Part, ngroups = 0, type = "cutree", optim = FALSE, 
            maxiter = 100, plotDendrogram = FALSE, verbose = FALSE)

Arguments

Details

The criterion for optimal consensus is the mean adjusted Rand Index between the consensus and the partitions given by the subjects.

If ngroups=0, consensus is computed between 2 and nstimuli-1 and the best consensus is returned.

For type="cutree", the initialisation step is based on cutting the tree generated by clustering the stimuli. For type="fusion", the initialisation step is based on the fusion algorithm. In this case, results are more accurate but the algorithm might be time consuming. For type="medoid", the consensus is the closest partition to all the partitions given by subjects.

For optim=TRUE, a transfer step is performed after the initialisation step.

Value

List of following components:

References

Krieger & Green (1999) J. of Classification, 16:63-89

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  res<-ConsensusPartition(Aroma,ngroups=0,type="cutree")
  res
  ##res<-ConsensusPartition(Aroma,ngroups=0,type="fusion",optim=TRUE)
  ##res
  ##res<-ConsensusPartition(Aroma,type="medoid")
  ##res
  

Coocurrences

Description

Returns the matrix of cooccurrences between stimuli.

Usage

Cooccurrences(Part)

Arguments

Details

Returns the matrix of cooccurrences between stimuli (number of times two stimuli have been sorted in the same group).

Value

A matrix of cooccurrences (stimuli x stimuli).

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  MatCooc<-Cooccurrences(Aroma)

Description of a partition

Description

DescriptionPartition() shows a partition given by a subject.

Usage

  DescriptionPartition(Part, subject = 1, replicate = 1, Labels=NULL)

Arguments

Value

Returns the partition with labels of stimuli bracketted in groups.

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  DescriptionPartition(Aroma,subject=1)

Overall Dissimilarities between stimuli.

Description

Creates the matrix of dissimilarities between stimuli.

Usage

DissTot(Part)

Arguments

Value

The matrix of dissimilarities between stimuli (number of times that two stimuli have not been grouped)

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  DisTot<-DissTot(Aroma)

Dissimilarities between stimuli

Description

Creates a list of dissimilarity matrices from partitions given by the subjects.

Usage

Dissimil(Part)

Arguments

Details

In the case of free sorting data, a list of dissimilarity matrices (the length of the list is equal to the number of subjects).

In the case of multiple sorting, dissimilarity matrix for a subject is the sum of the dissimilarity matrices computed from each of the different partitions given by this subject.

Value

A list of dissimilarity matrices (one matrix for each subject).

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  ListDiss<-Dissimil(Aroma)

Computation of the stress of Mds solution

Description

MdsDimChoice() returns a table of stress values of Multidimensionnal scaling for different dimensions. The different dimensions to test are given as an argument of the function.

The Mds is based on smacof algorithm and may be metric or not metric.

Usage

MdsDimChoice(Part, dimen = c(2, 4), metric = FALSE,
        ties = "primary", itmax = 5000, eps = 1e-06)

Arguments

Value

Table of Kruskal stress for the chosen dimensions

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  tabres<-MdsDimChoice(Aroma)

Mds of a dissimilarity matrix

Description

Computes the multidimensional scaling of a matrix of dissimilarities between stimuli. Mds is based on smacof algorithm. The Mds configuration is rotated in order to get orthogonal dimensions sorted by decreasing variance.

Usage

MdsDiss(MatDissimil, ndim = 2, metric = TRUE, ties = "primary",
              itmax = 5000, eps = 1e-06)

Arguments

Value

List of the following components :

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  ListDissimil<-Dissimil(Aroma)
  MatDissim<-apply(simplify2array(ListDissimil),c(1,2),'sum')
  Mdsres<-MdsDiss(MatDissim)

Mds of sorting data

Description

MdsSort returns the results of the multidimensional scaling of a list of dissimilarities. The Mds is based on smacof algorithm and may be metric or not metric.

Botstrap on subjects allows to draw confidence regions for the stimuli.

Usage

MdsSort(Part,ndim=2,nboot=0,metric=FALSE,ties="primary",itmax=5000,eps=1e-06)

Arguments

Value

An object of class SortingMds

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  resMds<-MdsSort(Aroma,ndim=2)

Rand Index between partitions

Description

Computes the Rand Index and the Adjusted Rand Index between two partitions

Usage

RandIndex(Partition1, Partition2)

Arguments

Details

Supports incomplete partitions (value 0 is coding for missing stimulus)

Value

List of following components:

References

Rand (1971) Jasa, 66, 846-850

Hubert & Arabie (1985) J. of Classification, 2, 193-218

Examples

  Partition1<-c(1,1,1,2,2,2)
  Partition2<-c(1,1,2,2,2,3)
  r<-RandIndex(Partition1,Partition2)
  r
  # $Rand
  # [1] 0.6
  # $AdjustedRand
  # [1] 0.1176471

Read a file of free sorting data

Description

The function (ReadSortFile()) reads a csv file of free sorting data.

The file contains stimuli as rows and subjects as columns. For a subject, two stimuli in the same group are coded by the same symbol. First row contains the labels of subjects and first column contains the labels of stimuli.

For each subject, the coding of a group may be a number or a list of terms describing the group (terms have to be separated by a symbol, as a comma).

Returns a matrix of sorting and, if this is adequate, matrices describing the use of terms by subjects.

Usage

ReadSortFile(filename, terms=FALSE, septerms=",", sep=";", dec=".")

Arguments

Value

List of the following components :

Examples

  # dat<-ReadSortFile ("FSdata.csv")
  # Sort<-SortingPartition(dat$MatSort)

Class SortingMds

Description

A class for Mds results

Objects from the Class

Objects are created by the function MdsSort().

Slots

nstimuli:

Number of stimuli

nsubjects:

Number of subjects

LabStim:

Labels of stimuli

LabSubj:

Labels of subjects

ndim:

Dimension of the Mds

Config:

Array of the configuration of stimuli

Percent:

Vector of inertia of the dimensions

Stress:

Kruskal stress of the configuration

ResBoot:

(optional) Results of bootstrap on the subjects

Methods

getConfig

signature(object = "SortingMds")

getPercent

signature(object = "SortingMds")

getStress

signature(object = "SortingMds")

show

show(object = "SortingMds")

summary

summary(object = "SortingMds")

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  resMds<-MdsSort(Aroma,ndim=2,metric=FALSE)
  summary(resMds)

Creates an object of class SortingPartition

Description

Returns an object of class SortingPartition from an array containing the partitions.

The array has stimuli as rows and subjects as columns. For a subject, two stimuli in the same group are coded by the same number.

Usage

  SortingPartition(DataSort)

Arguments

Details

The first row contains the labels of subjects and the first column contains the labels of stimuli.

In the case of multiple sorting task, the different partitions given by the same subject are in columns sharing the same name (but with different subnames: A, A.1, A.2...) in the array.

A value of 0 indicates that the subject did not sort the given stimulus (in case of incomplete design).

Value

An object of class SortingPartition.

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  show(Aroma)

Class SortingPartition

Description

A class for free sorting data

Objects from the Class

Objects can be created from an array by calls of the form SortingPartition().

Slots

type:

Type of sorting procedure : type="Free" or type="Multiple"

nstimuli:

Number of stimuli

nsubjects:

Number of subjects

LabStim:

Labels of stimuli

LabSubj:

Labels of subjects

Partition:

List of partitions of the stimuli given by subjects

Methods

show

show(object = "SortingPartition")

summary

summary(object = "SortingPartition")

getPartition

getPartition(object = "SortingPartition")

nGroups

nGroups(object = "SortingPartition")

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  summary(Aroma)
  show(Aroma)
  getPartition(Aroma)

Gets the Mds configuration.

Description

Gets the Mds config resulting from the function MdsSort().

Usage

getConfig(object)

Arguments

Value

An array of Mds configuration

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  resMds<-MdsSort(Aroma,ndim=2)
  config<-getConfig(resMds)

Gets the partitions.

Description

Returns an array of the partitions given by the subjects.

Usage

getPartition(object)

Arguments

Value

An array of the stimuli as rows and the partitions as columns.

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  part<-getPartition(Aroma)

Gets the percentages of variance

Description

Returns the percentage of variance explained by the dimensions of a Mds solution returned by the function MdsSort().

Usage

getPercent(object)

Arguments

Value

A vector of percentage of variance of the Mds configuration.

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  resMds<-MdsSort(Aroma,ndim=2)
  perc<-getPercent(resMds)

Gets the stress value

Description

Get the Kruskal stress value of the Mds solution returned by the function MdsSort().

Usage

getStress(object)

Arguments

Value

A numeric value of stress.

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  resMds<-MdsSort(Aroma,ndim=2)
  stress<-getStress(resMds)

Number of groups given by the subjects

Description

Returns the number of groups given by the subjects of a free sorting experiment.

Usage

nGroups(object)

Arguments

Value

A vector giving the number of groups made by the subjects

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  nGroups(Aroma)

Plot of the configuration of Mds

Description

plotMds returns a plot of the configuration resulting from a Multidimensionnal scaling.

Confidence ellipsoids are plotted if a bootstrap approach has been used in the MdsSort() step.

Usage

plotMds(ResMds, dim=c(1,2), ellipse=FALSE, proba=0.90, col=NULL)

Arguments

Value

plot of Mds configuration

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  resMds<-MdsSort(Aroma,ndim=2)
  plotMds(resMds)

Plot of the terms used during verbalisation step

Description

plotTerms() produces a plot of the terms. The rows of array MatTerms are the stimuli and the columns are the terms.

Usage

plotTerms(MatTerms,ResMds,dim=c(1,2),type="correl",add=TRUE)

Arguments

Details

If type="correl", the correlations between occurrences of terms and dimensions of a Mds configuration are plotted. plotTerms() returns the correlation matrix.

If type="baryc", a barycentric representation of terms is used. If add=TRUE, the stimuli are added to this plot. plotTerms() returns the coordinates of terms.

Value

returns a matrix of correlation or a configuration of terms (depending on type).

Examples

  data(AromaSort)
  Aroma<-SortingPartition(AromaSort)
  resMds<-MdsSort(Aroma,ndim=2)
  data(AromaTerms)
  plotTerms(AromaTerms,resMds)