# dummify

##### Convert Data to Numeric Values by Constructing Dummy Variables

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

- Keywords
- math

##### 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.

##### 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)
```

*Documentation reproduced from package spatstat, version 1.28-1, License: GPL (>= 2)*