# dstatis.inter: Dual STATIS method (interstructure stage) In dad: Three-Way / Multigroup Data Analysis Through Densities

 dstatis.inter R Documentation

## Dual STATIS method (interstructure stage)

### Description

Performs the first stage (interstructure) of the dual STATIS method in order to describe a data folder, consisting of `T` groups of individuals on which are observed `p` variables. It returns an object of class `dstatis`.

### Usage

``````dstatis.inter(xf, normed = TRUE, centered = TRUE, data.scaled = FALSE, nb.factors = 3,
nb.values = 10, sub.title = "", plot.eigen = TRUE, plot.score = FALSE,
nscore = 1:3, group.name = "group", filename = NULL)
``````

### Arguments

 `xf` object of class `folder`. Its elements are data frames with `p` numeric columns. If there are non numeric columns, there is an error. The `t^{th}` element (`t = 1, \ldots, T`) matches with the `t^{th}` group. `normed` logical. If `TRUE` (default), the scalar products are normed. `centered` logical. If `TRUE` (default), the scalar products are centered. `data.scaled` logical. If `TRUE`, the data of each group are centered and scaled. The analysis is then performed on the correlation matrices. If `FALSE` (default), the analysis is performed on the covariance matrices. `nb.factors` numeric. Number of returned principal scores (default `nb.factors = 3`). `nb.values` numerical. Number of returned eigenvalues (default `nb.values = 10`). `sub.title` string. If provided, the subtitle for the graphs. `plot.eigen` logical. If `TRUE` (default), the barplot of the eigenvalues is plotted. `plot.score` logical. If `TRUE`, the graphs of principal scores are plotted. A new graphic device is opened for each pair of principal scores defined by `nscore` argument. `nscore` numeric vector. If `plot.score = TRUE`, the numbers of the principal scores which are plotted. By default it is equal to `nscore = 1:3`. Its components cannot be greater than `nb.factors`. `group.name` string. Name of the grouping variable. Default: `groupname = "group"`. `filename` string. Name of the file in which the results are saved. By default (`filename = NULL`) the results are not saved.

### Details

The covariance matrices (if `data.scale` is `FALSE`) or correlation matrices (if `TRUE`) per group are computed. The matrix `W` of the scalar products between these covariance matrices is then computed.

To perform the STATIS method, see the function DSTATIS of the `multigroup` package.

### Value

Returns an object of class `dstatis`, that is a list including:

 `inertia ` data frame of the eigenvalues and percentages of inertia. `contributions ` data frame of the contributions to the first `nb.factors` principal components. `qualities ` data frame of the qualities on the first `nb.factors` principal factors. `scores ` data frame of the first `nb.factors` scores of the spectral decomposition of `W`. `norm ` vector of the `L^2` norms of the densities. `means ` list of the means. `variances ` list of the covariance matrices. `correlations ` list of the correlation matrices. `skewness ` list of the skewness coefficients. `kurtosis ` list of the kurtosis coefficients.

### Author(s)

Rachid Boumaza, Pierre Santagostini, Smail Yousfi, Gilles Hunault, Sabine Demotes-Mainard

### References

Lavit, C., Escoufier, Y., Sabatier, R., Traissac, P. (1994). The ACT (STATIS method). Computational Statistics & Data Analysis, 18 (1994), 97-119.

print.dstatis, plot.dstatis, interpret.dstatis.

DSTATIS

### Examples

``````data(roses)
rosesf <- as.folder(roses[,c("Sha","Den","Sym","rose")])

# Dual STATIS on the covariance matrices
result1 <- dstatis.inter(rosesf, data.scaled = FALSE, group.name = "rose")
print(result1)
plot(result1)

# Dual STATIS on the correlation matrices
result2 <- dstatis.inter(rosesf, data.scaled = FALSE, group.name = "rose")
print(result2)
plot(result2)
``````

dad documentation built on Aug. 30, 2023, 5:06 p.m.