Changing colour gradient in Spatstat surface plot

Graham Smith <graham.smith at myotis.co.uk> writes:
I have produced a smoothed surface plot of
water depths (depths as marks) in spatstat, but the default colours
are oranges and reds. How do I change these to blues.
Can I redifne the colours in terrain.colors() or topo.colors(), or do
I need to use rainbow(). Or is its something different all together.
Yes, you can do all of these things. It is not true that the colours are
hard-wired.
I have tried the options I listed above , but can't get a syntax that
works, and haven't found the help any help at all (not for me anyway).
I presume that you are using smooth.ppp to smooth a marked point pattern,
yielding a pixel image (object of class "im") which you now want to
display in your chosen colours. So the relevant help file is
               help(plot.im)
The help file explains that the argument 'col' determines the colours that
will be used. See the examples in the help file, or example(plot.im).

Here is an example of the whole process, starting from a marked point
pattern and finishing with a colour image:

      library(spatstat)
      data(longleaf)
      Z <- smooth.ppp(longleaf)
      plot(Z)
      plot(Z, col=topo.colors(256))

Adrian Baddeley
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Maybe this synthesis of both replies can help you:

library(RColorBrewer)
bl5 <- brewer.pal(5, "Blues")
mypal <- colorRampPalette(bl5)

  library(spatstat)
  data(longleaf)
  Z <- smooth.ppp(longleaf)
  plot(Z)
  plot(Z, col=mypal(12))

#or

plot(Z, col=rev(mypal(12)))

Regards,

Marcelino
Adrian

Thanks for the reply

Here is an example of the whole process, starting from a marked point
pattern and finishing with a colour image:

      library(spatstat)
      data(longleaf)
      Z <- smooth.ppp(longleaf)
      plot(Z)
      plot(Z, col=topo.colors(256))
This is what I did, but I couldn't find, and still can't find,
anything in the help for plot.im or topo,colors that explains how to
change the colours to graduated blue, am  being really dim here.

However, in another post it was suggested I use rColorbrewer to set
up the colours , but it worries me that I cannot find the bit in the
help you have sent me to.

Graham
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________________________________

Marcelino de la Cruz Rot

Departamento de  Biolog?a Vegetal
E.U.T.I. Agr?cola
Universidad Polit?cnica de Madrid
28040-Madrid
Tel.: 91 336 54 35
Fax: 91 336 56 56
marcelino.delacruz at upm.es