dudi.coa: Correspondence Analysis

Description Usage Arguments Value Author(s) References Examples

Description

performs a correspondence analysis.

Usage

1
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 [email protected]

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

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
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

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

Example output

X-squared 
 7323.597 
Warning message:
In chisq.test(rpjdl$fau) : Chi-squared approximation may be incorrect
[1] 7323.597
Duality diagramm
class: coa dudi
$call: dudi.coa(df = bordeaux, scannf = FALSE)

$nf: 2 axis-components saved
$rank: 3
eigen values: 0.5906 0.1102 0.03109
  vector length mode    content       
1 $cw    4      numeric column weights
2 $lw    5      numeric row weights   
3 $eig   3      numeric eigen values  

  data.frame nrow ncol content             
1 $tab       5    4    modified array      
2 $li        5    2    row coordinates     
3 $l1        5    2    row normed scores   
4 $co        4    2    column coordinates  
5 $c1        4    2    column normed scores
other elements: N 

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

Related to dudi.coa in ade4...