spam (version 1.4-0)

display: Graphially Represent the Nonzero Entries

Description

The function represents the nonzero entries in a simple bicolor plot.

Usage

display(x, ...)

Arguments

x

matrix of class spam or spam.chol.NgPeyton.

...

any other arguments passed to image.default/plot.

Details

spam.getOption("imagesize") determines if the sparse matrix is coerced into a matrix and the plotted with image.default or if the matrix is simply represented as a scatterplot with pch=".". The points are scaled according to cex*spam.getOption("cex")/(nrow + ncol). For some devices or for non-square matrices, cex needs probably some adjustment.

See Also

image, spam.options

Examples

set.seed(13)

nz <- 8
ln <- nz
smat <- spam(0, ln, ln)
smat[cbind(sample(ln, nz), sample(ln, nz))] <- 1:nz

par(mfcol=c(1,2), pty='s')
spam.options(imagesize = 1000)
display(smat)
spam.options(imagesize = 10)
display(smat)


# very large but very sparse matrix
nz <- 128
ln <- nz^2
smat <- spam(0, ln, ln)
smat[cbind(sample(ln, nz), sample(ln, nz))] <- 1:nz

par(mfcol=c(1, 1), pty='s')
display(smat, cex = 100)