summary.ca: Summarizing simple correspondence analysis

In ca: Simple, Multiple and Joint Correspondence Analysis

Description

Printed output summarizing the results of ca, including a scree-plot of the principal inertias and row and column contributions.

Usage

## S3 method for class 'ca'
summary(object, scree = TRUE, rows=TRUE, columns=TRUE, ...)

Arguments

object	Simple correspondence analysis object returned by ca.
scree	Logical flag specifying if a scree-plot should be included in the output.
rows	Logical: should row contribution summaries be included?
columns	Logical: should column contribution summaries be included?
...	Further arguments (ignored)

Details

The function summary.ca gives the detailed numerical results of the ca function. All the eigenvalues (principal inertias) are listed, their percentages with respect to total inertia, and a bar chart (also known as a scree plot). Then for the set of rows and columns a table of results is given in a standard format, where quantities are either multiplied by 1000 or expressed in permills (thousandths): the mass of each point (x1000), the quality of display in the solution subspace of nd dimensions, the inertia of the point (in permills of the total inertia), and then for each dimension of the solution the principal coordinate (x1000), the (relative) contribution COR of the principal axis to the point inertia (x1000) and the (absolute) contribution CTR of the point to the inertia of the axis (in permills of the principal inertia).
For supplementary points, masses, inertias and absolute contributions (CTR) are not applicable, but the relative contributions (COR) are valid as well as their sum over the set of chosen nd dimensions (QLT).

Examples

data("smoke")
summary(ca(smoke))

Example output

Principal inertias (eigenvalues):

 dim    value      %   cum%   scree plot               
 1      0.074759  87.8  87.8  **********************   
 2      0.010017  11.8  99.5  ***                      
 3      0.000414   0.5 100.0                           
        -------- -----                                 
 Total: 0.085190 100.0                                 


Rows:
    name   mass  qlt  inr    k=1 cor ctr    k=2 cor ctr  
1 |   SM |   57  893   31 |  -66  92   3 | -194 800 214 |
2 |   JM |   93  991  139 |  259 526  84 | -243 465 551 |
3 |   SE |  264 1000  450 | -381 999 512 |  -11   1   3 |
4 |   JE |  456 1000  308 |  233 942 331 |   58  58 152 |
5 |   SC |  130  999   71 | -201 865  70 |   79 133  81 |

Columns:
    name   mass  qlt  inr    k=1 cor ctr    k=2 cor ctr  
1 | none |  316 1000  577 | -393 994 654 |  -30   6  29 |
2 | lght |  233  984   83 |   99 327  31 |  141 657 463 |
3 | medm |  321  983  148 |  196 982 166 |    7   1   2 |
4 | hevy |  130  995  192 |  294 684 150 | -198 310 506 |

ca documentation built on May 2, 2019, 6:12 p.m.