R: Convert Data to Numeric Values by Constructing Dummy...

dummify {spatstat.core} | R Documentation

## Convert Data to Numeric Values by Constructing Dummy Variables

### Description

Converts data of any kind to numeric values. A factor is expanded to a set of dummy variables.

### Usage

    dummify(x)

### Arguments

`x` | Vector, factor, matrix or data frame to be converted.

### Details

This function converts data (such as a factor) to numeric values in order that the user may calculate, for example, the mean, variance, covariance and correlation of the data.

If `x` is a numeric vector or integer vector, it is returned unchanged.

If `x` is a logical vector, it is converted to a 0-1 matrix with 2 columns. The first column contains a 1 if the logical value is `FALSE`, and the second column contains a 1 if the logical value is `TRUE`.

If `x` is a complex vector, it is converted to a matrix with 2 columns, containing the real and imaginary parts.

If `x` is a factor, the result is a matrix of 0-1 dummy variables. The matrix has one column for each possible level of the factor. The `(i,j)` entry is equal to 1 when the `i`th factor value equals the `j`th level, and is equal to 0 otherwise.

If `x` is a matrix or data frame, the appropriate conversion is applied to each column of `x`.

Note that, unlike `model.matrix`, this command converts a factor into a full set of dummy variables (one column for each level of the factor).

### Value

A numeric matrix.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

### Examples

       chara <- sample(letters[1:3], 8, replace=TRUE)
       logi <- (runif(8) < 0.3)
       comp <- round(4*runif(8) + 3*runif(8) * 1i, 1)
       nume <- 8:1 + 0.1
       df <- data.frame(nume, chara, logi, comp)
       df
       dummify(df)

[Package spatstat.core version 2.4-4 Index]