R help - Oct 2015 - changing colors in filled.contour

Dear R community!

I haven't worked with R before but I found it has some nice abilities to
create graphics. I made it to create a filled.contour with the settings I
want but unfortunately I don't seem to be able to change colors. Instead of
the standard colors, I'd like to get dark gray or black for higher values
(instead of pink) and light gray or white for lower values (instead of
cyan).  A second option I'd like to try is having colors change from green
(low values) to red (high values)... but right now it seems like I'm miles
away from that.

This is what I have so far:

model=function(a, b){+4+0.5*a-0.2*b}
x=seq(-10, 10, by = 2)
y=seq(0, 100, by = 10)
z=outer(x, y, model)
contour(x,y,z,nlevels=12)
mylevels <- seq(0,10,10)
filled.contour(x,y,z, main="Title")

But when I try to Change the Color theme like this -

filled.contour(x,y,z,levels=mylevels,col=grey(seq(0,1,length=length(mylevels))))

 - I just get one white and one black bar. 

Does anyone of you know a solution?

Thanks in advance, you'd help me a lot as I've been working on these few
lines for a couple already.

J




--
View this message in context:
http://r.789695.n4.nabble.com/changing-colors-in-filled-contour-tp4713260.html
Sent from the R help mailing list archive at Nabble.com.

After
     mylevels <- seq(0,10,10)
mylevels has length 2, hence you get 2 colors.  Use length=10,


Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Wed, Oct 7, 2015 at 3:40 AM, begrinner <j.terheyden at t-online.de>
wrote:
> Dear R community!
>
> I haven't worked with R before but I found it has some nice abilities
to
> create graphics. I made it to create a filled.contour with the settings I
> want but unfortunately I don't seem to be able to change colors.
Instead of
> the standard colors, I'd like to get dark gray or black for higher
values
> (instead of pink) and light gray or white for lower values (instead of
> cyan).  A second option I'd like to try is having colors change from
green
> (low values) to red (high values)... but right now it seems like I'm
miles
> away from that.
>
> This is what I have so far:
>
> model=function(a, b){+4+0.5*a-0.2*b}
> x=seq(-10, 10, by = 2)
> y=seq(0, 100, by = 10)
> z=outer(x, y, model)
> contour(x,y,z,nlevels=12)
> mylevels <- seq(0,10,10)
> filled.contour(x,y,z, main="Title")
>
> But when I try to Change the Color theme like this -
>
>
>
filled.contour(x,y,z,levels=mylevels,col=grey(seq(0,1,length=length(mylevels))))
>
>  - I just get one white and one black bar.
>
> Does anyone of you know a solution?
>
> Thanks in advance, you'd help me a lot as I've been working on
these few
> lines for a couple already.
>
> J
>
>
>
>
> --
> View this message in context:
>
http://r.789695.n4.nabble.com/changing-colors-in-filled-contour-tp4713260.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
	[[alternative HTML version deleted]]

Thanks a lot! 
I see more bars now but still, more than half of the diagram is white now.
Any suggestion to change that?

And is it possible to invert the color scheme?  (black does now stand for
lower values instead of higher ones)
  mylevels <- seq(10,0,length=10)  does not seem to work.



--
View this message in context:
http://r.789695.n4.nabble.com/changing-colors-in-filled-contour-tp4713260p4713319.html
Sent from the R help mailing list archive at Nabble.com.