INDSCAL: weighted MDS with individual differences

Carroll & Chang (1970) weighted MDS with a shared stimulus space and per-individual dimension weights.

Usage

morie_spatial_voting_indscal(
  dissimilarities,
  n_dims = 2L,
  max_iter = 300L,
  tol = 1e-06
)

Arguments

dissimilarities

List of (n_stim x n_stim) dissimilarity matrices.

n_dims

Number of dimensions.

max_iter

Maximum ALS iterations.

tol

Convergence tolerance on configuration change.

Value

List with group_config, weights, stress, iterations, n_individuals, n_stimuli.

References

Carroll, J. D. and Chang, J.-J. (1970). "Analysis of Individual Differences in Multidimensional Scaling via an N-way Generalization of Eckart-Young Decomposition." Psychometrika, 35(3).

Examples

D1 <- as.matrix(dist(matrix(rnorm(20), 5)))
D2 <- as.matrix(dist(matrix(rnorm(20), 5)))
morie_spatial_voting_indscal(list(D1, D2), n_dims = 2L, max_iter = 30L)
#> $group_config
#>              [,1]         [,2]
#> [1,] 2.388251e-27 1.095416e-29
#> [2,] 1.200412e-28 1.758657e-31
#> [3,] 5.718241e-32 3.470631e-34
#> [4,] 7.156697e-33 4.229960e-35
#> [5,] 6.382413e-34 2.816561e-36
#> 
#> $weights
#>         [,1]    [,2]
#> [1,] 2054187 2054187
#> [2,] 1929831 1929831
#> 
#> $stress
#> [1] 298.3059
#> 
#> $iterations
#> [1] 8
#> 
#> $n_individuals
#> [1] 2
#> 
#> $n_stimuli
#> [1] 5
#>