spam (version 0.11)

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.

...

any other arguments passed to image.default/plot.

Details

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

See Also

image, .Spam

Examples

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$imagesize <- 1000
display(smat)
.Spam$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)