R: Efficiently Count Positive, Negative and Zero Values...

signcount {wordspace} | R Documentation

## Efficiently Count Positive, Negative and Zero Values (wordspace)

### Description

This function counts the number of positive, negative and zero elements in a numeric vector or matrix, including some types of dense and sparse representations in the `Matrix` package.

It can be used to test for non-negativity and compute nonzero counts efficiently, without any memory overhead.

### Usage

    signcount(x, what = c("counts", "nonneg", "nnzero"))

### Arguments

`x` | a numeric vector or array, or a numeric `Matrix` (supported formats are `dgeMatrix`, `dgCMatrix` and `dgRMatrix`)
`what` | whether to return the counts of positive, negative and zero elements (`counts`), the number of nonzero elements (`nnzero`), or to test for non-negativity (`nonneg`); see ‘Value’ below

### Details

`x` must not contain any undefined values; `signcount` does not check whether this is actually the case.

### Value

`what="counts"`

  A labelled numeric vector of length 3 with the counts of positive (`pos`), zero (`zero`) and negative (`neg`) values.

`what="nonneg"`

  A single logical value: `TRUE` if `x` is non-negative, `FALSE` otherwise.

`what="nonzero"`

  A single numeric value, the total number of nonzero elements in `x`.

### Author(s)

Stefan Evert (http://purl.org/stefan.evert)

### Examples

    signcount(DSM_TermTermMatrix)     # dense matrix
    signcount(DSM_TermContextMatrix)  # sparse dgCMatrix
    signcount(DSM_TermContextMatrix, "nonneg") # confirm that it is non-negative

[Package wordspace version 0.2-6 Index]