[R] barplot: different colors for the bar and the strips

[Marc Schwartz (via MN)]

On Thu, 2006-09-07 at 12:14 -0500, Hao Chen wrote:
> Hello Marc Schwartz
> 
> On Thu, Sep 07, 2006 at 07:54:05AM -0500, Marc Schwartz wrote:
> > On Thu, 2006-09-07 at 06:18 -0500, Hao Chen wrote:
> > > Hi,
> > > 
> > > I am using barplot and would like to know if it is possible to have bars
> > > filled with one color while use a different color for the shading lines. 
> > > 
> > > The following code colors the shading lines, leaving the bars in white:
> > > 
> > >  barplot(1:5, col=c(1:5), density=c(1:5)*5)
> > > 
> > > while the colors are applied to the bars when density is removed.
> > > 
> > >  barplot(1:5, col=c(1:5))
> > > 
> > > I did check ?barplot and found the following: 
> > > 
> > > 	col: a vector of colors for the bars or bar components. 
> > >  
> > >  Thanks,
> > > 
> > >  Hao
> > 
> > Note the key word 'or' in the description of the 'col' argument.
> > 
> > You need to make two separate calls to barplot(). The first using the
> > fill colors, then the second using the shading lines AND setting 'add =
> > TRUE', so that the second plot overwrites the first without clearing the
> > plot device.
> > 
> >  barplot(1:5, col=c(1:5))
> > 
> >  barplot(1:5, col = "black", density=c(1:5), add = TRUE)
> > 
> > Just be sure that any other arguments, such as axis limits, are
> > identical between the two calls.
> > 
> > HTH,
> > 
> > Marc Schwartz
> > 
> 
> 
> Thank you very much for your help. It works but only in the order as you
> put it, since the following code only shows the color, but not the
> shading lines:
> 
> barplot(1:5, col = "black", density=c(1:5))
> barplot(1:5, col=c(1:5), add = TRUE)
> 
> Hao Chen

That is correct. The sequence is important, as the shading lines are
drawn with a transparent background, enabling the original color to be
seen.

Reversing the order, you are overplotting the shading lines with opaque
colored rectangles. Hence, the lines are lost.

HTH,

Marc