## Correspondence Analysis

### Description

performs a correspondence analysis.

### Usage

```dudi.coa(df, scannf = TRUE, nf = 2)
```

### Arguments

 `df` a data frame containing positive or null values `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

### Value

returns a list of class `coa` and `dudi` (see dudi) containing

 `N` the sum of all the values of the initial table

### Author(s)

Daniel Chessel
Anne B Dufour anne-beatrice.dufour@univ-lyon1.fr

### References

Benzécri, J.P. and Coll. (1973) L'analyse des données. II L'analyse des correspondances, Bordas, Paris. 1–620.

Greenacre, M. J. (1984) Theory and applications of correspondence analysis, Academic Press, London.

### Examples

```data(rpjdl)
chisq.test(rpjdl\$fau)\$statistic
rpjdl.coa <- dudi.coa(rpjdl\$fau, scannf = FALSE, nf = 4)
sum(rpjdl.coa\$eig)*rpjdl.coa\$N # the same

g1 <- s.label(rpjdl.coa\$co, plab.cex = 0.6, lab = rpjdl\$frlab, plot = FALSE)
g2 <- s.label(rpjdl.coa\$li, plab.cex = 0.6, plot = FALSE)
} else {
par(mfrow = c(1,2))
s.label(rpjdl.coa\$co, clab = 0.6, lab = rpjdl\$frlab)
s.label(rpjdl.coa\$li, clab = 0.6)
par(mfrow = c(1,1))
}

data(bordeaux)
db <- dudi.coa(bordeaux, scan = FALSE)
db
score(db)
```