R: Get Type

get.type {lpSolveAPI} | R Documentation

## Get Type

### Description

Retrieve the type of a decision variable from an lpSolve linear program model object.

### Usage

    get.type(lprec, columns = 1:n, as.char = TRUE)

### Arguments

`lprec` | an lpSolve linear program model object.
`columns` | a numeric vector of unique values from the set `{1, ..., n}` (where `n` is the number of decision variables in `lprec`) specifying the columns for which the type will be retrieved.
`as.char` | a logical value. If `TRUE` the constraint type is returned as a character string, otherwise the integer code used internally by lpSolve is returned.

### Details

The function `set.type` can be used to set a decision variable as binary. A binary decision variable is simply an integer decision with an upper bound of one and a lower bound of zero - hence this function will report the type as integer.

### Value

either a character vector with elements from the set `{"real", "integer"}` indicating the type of each decision variable specified in `columns` or (if `as.char = FALSE`) a logical vector with `TRUE` elements corresponding to the integer decision variables specified in `columns`.

### Author(s)

Kjell Konis kjell.konis@me.com

### References

http://lpsolve.sourceforge.net/5.5/index.htm

### See Also

`set.type`

### Examples

    lps.model <- make.lp(0, 3)
    xt <- c(6,2,4)
    add.constraint(lps.model, xt, "<=", 150)
    xt <- c(1,1,6)
    add.constraint(lps.model, xt, ">=", 0)
    set.type(lps.model, 2, "binary")
    xt <- c(4,5,4)
    add.constraint(lps.model, xt, "=", 40)
    set.type(lps.model, 3, "integer")
    set.objfn(lps.model, c(-3,-4,-3))

    get.type(lps.model)

[Package lpSolveAPI version 5.5.2.0-17 Index]