I found a terrific package grImport for reading in .ps files (vector vs. raster). It works very well and the reader can find the package info here:
http://cran.r-project.org/web/packages/grImport/grImport.pdf
and a demo here:
https://www.stat.auckland.ac.nz/~paul/R/grImport/import.pdf
I'd like to be able to change the color of slots in an object of the class Picture but can not figure out how. So using this code:
library(grImport); library(grid)
## Create a generic .ps file to read in
postscript("foo.ps")
plot.new()
text(.5, 0.5, "A", cex = 45)
dev.off()
## read in the .ps object
PostScriptTrace("foo.ps")
foo <- readPicture("foo.ps.xml")
grid.picture(foo)
How can I alter the object foo to make the A plot as a light grey, say #D0D0D0?
I tried:
class(foo)
foo
foo@rgb
I assume this is an S4 object which may be why I am struggling (I lack familiarity with s4).
Use str to explore the structure of the S4 object:
R> str(foo)
Formal class 'Picture' [package "grImport"] with 2 slots
..@ paths :List of 1
.. ..$ text:Formal class 'PictureText' [package "grImport"] with 14 slots
.. .. .. ..@ string : Named chr "A"
.. .. .. .. ..- attr(*, "names")= chr "string"
.. .. .. ..@ w : num 3602
.. .. .. ..@ h : num 5400
.. .. .. ..@ bbox : num [1:4] 904 2644 4840 6154
.. .. .. ..@ angle : num 90
.. .. .. ..@ letters :List of 1
...
The color can be changed in the following way:
foo@paths$text@letters$path@rgb <- "#D0D0D0"