[R] Error in plot.new() : Figure margins too large

[Antje]

Hello,

was could be the reason for such an error message???
I'd like to create a window with 10x6 barplot and save it as pdf.

I tried:

pdf("histogram.pdf",width=7, height=7)

windows(cols, rows)
par(mfcol = c(rows,cols))

sapply(mat, calcHist)

dev.off()

Within the method of sapply, I call barplot

What is wrong???

Antje