On Jun 12, 2013, at 12:37 PM, Dan Abner dan.abne...@gmail.com wrote:
Hi everyone,
I have the following call to the barplot() function which produces the
desired stacked bar chart. HOWEVER, barplot() chooses 4 different shades of
gray for the stacks. If I want to use the legend=NULL argument in
combination with a separate call to legend() to customize the legend, how
do I figure out exactly what shades of gray barplot() has choosen? Can
these color names be extracted from the barplot after saving it as an
object?
barplot(table(credit_rating_num,clu_),
xlab=Cluster Label,
ylab=Frequency,
ylim=c(0,7000),
legend=c(C2,C3,C4,C5))
Thank you,
Dan
The help file defines the 'col' argument as:
col a vector of colors for the bars or bar components. By default, grey is
used if height is a vector, and a gamma-corrected grey palette if height is a
matrix.
However, that is lacking a bit of detail in the latter case, albeit one of the
examples on the page uses the gray.colors() function.
The easiest way to get that detail (in this case or for any function more
generally) is to look at the source code for the function, within which you
would see:
...
else if (is.matrix(height)) {
if (is.null(col))
col - gray.colors(nrow(height))
...
A better approach would be to simply take proactive control of the colors when
you call barplot() and define the 'col' argument to colors of your choosing,
which you can then use in the call to legend().
Regards,
Marc Schwartz
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
