R: Convert a table with counts to a matrix or data.frame...

table2matrix {psych} | R Documentation

## Convert a table with counts to a matrix or data.frame representing those counts.

### Description

Some historical sets are reported as summary tables of counts in a limited number of bins. Transforming these tables to data.frames representing the original values is useful for pedagogical purposes. (E.g., transforming the original Galton table of height x cubits in order to demonstrate regression.) The column and row names must be able to be converted to numeric values.

### Usage

    table2matrix(x, labs = NULL)
    table2df(x, count=NULL,labs = NULL)

### Arguments

`x` | A two dimensional table of counts with row and column names that can be converted to numeric values.
`count` | if present, then duplicate each row count times
`labs` | Labels for the rows and columns. These will be used for the names of the two columns of the resulting matrix

### Details

The original Galton (1888) of heights by cubits (arm length) is in tabular form. To show this as a correlation or as a scatter plot, it is useful to convert the table to a matrix or data frame of two columns.

This function may also be used to convert an item response pattern table into a data table. e.g., the Bock data set `bock`.

### Value

A matrix (or data.frame) of sum(x) rows and two columns.

### Author(s)

William Revelle

### See Also

`cubits` and `bock` data sets

### Examples

    data(cubits)
    cubit <- table2matrix(cubits,labs=c("height","cubit"))
    describe(cubit)
    ellipses(cubit,n=1)
    data(bock)
    responses <- table2df(bock.table[,2:6],count=bock.table[,7],labs= paste("lsat6.",1:5,sep=""))
    describe(responses)

[Package psych version 1.7.3.21 Index]