# witwit.coa: Internal Correspondence Analysis In ade4: Analysis of Ecological Data : Exploratory and Euclidean Methods in Environmental Sciences

## Description

`witwit.coa` performs an Internal Correspondence Analysis. `witwitsepan` gives the computation and the barplot of the eigenvalues for each separated analysis in an Internal Correspondence Analysis.

## Usage

 ```1 2 3 4``` ```witwit.coa(dudi, row.blocks, col.blocks, scannf = TRUE, nf = 2) ## S3 method for class 'witwit' summary(object, ...) witwitsepan(ww, mfrow = NULL, csub = 2, plot = TRUE) ```

## Arguments

 `dudi` an object of class `coa` `row.blocks` a numeric vector indicating the row numbers for each block of rows `col.blocks` a numeric vector indicating the column numbers for each block of columns `scannf` a logical value indicating whether the eigenvalues bar plot should be displayed `nf` if scannf FALSE, an integer indicating the number of kept axes

 `object` an object of class `witwit` `...` further arguments passed to or from other methods

 `ww` an object of class `witwit` `mfrow` a vector of the form "c(nr,nc)", otherwise computed by a special own function 'n2mfrow' `csub` a character size for the sub-titles, used with `par("cex")*csub` `plot` if FALSE, numeric results are returned

## Value

returns a list of class `witwit`, `coa` and `dudi` (see as.dudi) containing

 `rbvar` a data frame with the within variances of the rows of the factorial coordinates `lbw` a data frame with the marginal weighting of the row classes `cvar` a data frame with the within variances of the columns of the factorial coordinates `cbw` a data frame with the marginal weighting of the column classes

## Author(s)

Daniel Chessel Anne B Dufour [email protected] Correction by Campo Elías PARDO [email protected]

## References

Cazes, P., Chessel, D. and Dolédec, S. (1988) L'analyse des correspondances internes d'un tableau partitionné : son usage en hydrobiologie. Revue de Statistique Appliquée, 36, 39–54.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17``` ```data(ardeche) coa1 <- dudi.coa(ardeche\$tab, scann = FALSE, nf = 4) ww <- witwit.coa(coa1, ardeche\$row.blocks, ardeche\$col.blocks, scann = FALSE) ww summary(ww) if(adegraphicsLoaded()) { g1 <- s.class(ww\$co, ardeche\$sta.fac, plab.cex = 1.5, ellipseSi = 0, paxes.dr = FALSE, plot = F) g2 <- s.label(ww\$co, plab.cex = 0.75, plot = F) G <- superpose(g1, g2, plot = TRUE) } else { s.class(ww\$co, ardeche\$sta.fac, clab = 1.5, cell = 0, axesell = FALSE) s.label(ww\$co, add.p = TRUE, clab = 0.75) } witwitsepan(ww, c(4, 6)) ```

ade4 documentation built on May 31, 2017, 4:06 a.m.