R help - Oct 2013 - colour code areas of a plot

Hi,

I would like to colour different areas of a plot.
But I don't know how to do this efficiently.

As an example;

lets say three stimuli were presented in an experiment, alternating, one at a
time.
Now I want to plot time on the x-axis and the plot-area should colour code the
stimulus that was presented at that time interval
(green for stimulus 1, yellow for stimulus 2 etc.)


here an example:
(t = time)


t <- 1:100
bg_colors <- c(rep('green',20), rep('yellow',10),
rep('green',20), rep('red',5), rep('yellow',45))

color_scheme <- data.frame(t, bg_colors)

plot(c(), c(), xlim = c(1,100), ylim=c(-1,1))


rect(xleft = 1, ybottom = -1, xright = 20, ytop = 1, col = 'green',
lwd=0)
rect(xleft = 20, ybottom = -1, xright = 30, ytop = 1, col = 'yellow',
lwd=0)
?


now how can I do this efficiently based on the color_scheme data-frame and
without having to manually draw all the rectangles as in the example above?



thanks for any suggestions!

Martin Batholdy <batholdy <at> googlemail.com>
writes:
> I would like to colour different areas of a plot.
> But I don't know how to do this efficiently.
> 
> here an example:
> (t = time)
> 
> t <- 1:100
> bg_colors <- c(rep('green',20), rep('yellow',10), 
rep('green',20), rep('red',5),
> rep('yellow',45)) 
> 
> color_scheme <- data.frame(t, bg_colors)
> 
> plot(c(), c(), xlim = c(1,100), ylim=c(-1,1))
> 
> rect(xleft = 1, ybottom = -1, xright = 20, ytop = 1, 
col = 'green', lwd=0) 
> rect(xleft = 20, ybottom = -1, xright = 30, ytop = 1, 
col = 'yellow', lwd=0) 
> ?
> 
> now how can I do this efficiently based on the c
olor_scheme data-frame
 and without having to manually draw
> all the rectangles as in the example above?
The first 4 arguments of rect can be vectors 
as can be the col argument.  So you might be able to
draw all of the regions with a single call to rect.
I've done this to create alternating light and dark
regions to highlight condition changes.
See ?rect, of course.
> 
> thanks for any suggestions!
> 
-- 
Kenneth Knoblauch
Inserm U846
Stem-cell and Brain Research Institute
Department of Integrative Neurosciences
18 avenue du Doyen L?pine
69500 Bron
France
tel: +33 (0)4 72 91 34 77
fax: +33 (0)4 72 91 34 61
portable: +33 (0)6 84 10 64 10
http://www.sbri.fr/members/kenneth-knoblauch.html

On Tue, 22 Oct 2013 16:43:18 +0200
Martin Batholdy <batholdy at googlemail.com> wrote:

Hi,

you should replace your "color names" by calls to the rgb() function
in
order to generate the adequate colors, something like:

bg_colors <- c(rep (rgb (0,1,0),20), rep (rgb (0,1,1),10), rep (rgb
(0,1,0),20), rep(rgb (1,0,0),5), rep(rgb (1,1,0),45)) 

(though it should obviously be automatically extracted from your data I
suppose).

Then it is possible to use the color vector as an option to
any plotting command e.g.:

plot(color_scheme$t, color_scheme$t,col=bg_colors)

or (something like):

rect(xleft = color_scheme$t[1:99], ybottom = -1, xright = color_scheme$t
[2:100], ytop = 1, col=bg_colors, lwd=0) 

Olivier.

> Hi,
> 
> I would like to colour different areas of a plot.
> But I don't know how to do this efficiently.
> 
> As an example;
> 
> lets say three stimuli were presented in an experiment, alternating,
> one at a time. Now I want to plot time on the x-axis and the
> plot-area should colour code the stimulus that was presented at that
> time interval (green for stimulus 1, yellow for stimulus 2 etc.)
> 
> 
> here an example:
> (t = time)
> 
> 
> t <- 1:100
> bg_colors <- c(rep('green',20), rep('yellow',10),
rep('green',20), rep
> ('red',5), rep('yellow',45)) 
> 
> color_scheme <- data.frame(t, bg_colors)
> 
> plot(c(), c(), xlim = c(1,100), ylim=c(-1,1))
> 
> 
> rect(xleft = 1, ybottom = -1, xright = 20, ytop = 1, col = 'green',
> lwd=0) rect(xleft = 20, ybottom = -1, xright = 30, ytop = 1, col >
'yellow', lwd=0) ?
> 
> 
> now how can I do this efficiently based on the color_scheme
> data-frame and without having to manually draw all the rectangles as
> in the example above?
> 
> 
> 
> thanks for any suggestions!
> ______________________________________________
> R-help at 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.

-- 
  Olivier Crouzet, PhD
  Laboratoire de Linguistique -- EA3827
  Universit? de Nantes
  Chemin de la Censive du Tertre - BP 81227
  44312 Nantes cedex 3
  France

     phone:        (+33) 02 40 14 14 05 (lab.)
                   (+33) 02 40 14 14 36 (office)
     fax:          (+33) 02 40 14 13 27
     e-mail:       olivier.crouzet at univ-nantes.fr
 		
  http://www.lling.univ-nantes.fr/