R: Pad matrix with zeros

padzeros {ptw} | R Documentation

## Pad matrix with zeros

### Description

Adds zeros to the left side of a matrix or vector, to its right side, or to both sides.

### Usage

    padzeros(data, nzeros, side="both")

### Arguments

`data` | the original matrix or vector
`nzeros` | number of columns to add on one side
`side` | to which side to add the zeros - choose between "`both`", "`left`" or "`right`"

### Details

When `data` is a numeric vector, it is converted to a matrix of a single row.

### Value

A matrix with the same number of rows as the original matrix, and extra columns containing zeros on the specified side or sides

### Author(s)

Jan Gerretzen

### References

Bloemberg, T.G., et al. (2010) "Improved parametric time warping for Proteomics", Chemometrics and Intelligent Laboratory Systems, 104 (1), 65 – 74.

### Examples

    data(lcms)
    lcms.z1 <- padzeros(lcms[75,,1], 250, side="left")
    lcms.z2 <- padzeros(lcms[75,,1], 250, side="right")
    lcms.z3 <- padzeros(lcms[75,,1], 250, side="both")
    zeros <- rep(0, 250)

    layout(matrix(1:4,2,2, byrow=TRUE))
    plot(lcms[75,,1], type="l", main="Original signal")

    plot(as.vector(lcms.z1), type="l", main="Padzeros left side")
    points(1:250, zeros, col=2, lwd=0.08)

    plot(as.vector(lcms.z2), type="l", main="Padzeros right side")
    points(2001:2250, zeros, col=2, lwd=0.08)

    plot(as.vector(lcms.z3), type="l", main="Padzeros both sides")
    points(1:250, zeros, col=2, lwd=0.08)
    points(2251:2500, zeros, col=2, lwd=0.08)

[Package ptw version 1.9-12 Index]