[R] Speeding up image plots
maik.heistermann at uni-potsdam.de
Mon Oct 1 11:27:11 CEST 2007
I wonder whether it is possible to speed up plots of 2-dimensional
images (such as image() or levelplot()) in order to export lower quality
versions of the resulting plots.
I intend to export a large number of images in order to construct
animated gifs. For this purpose, I used the png()-function in
conncection with image() and levelplot(). But the underlying arrays are
so big (900x900 entries) that the export of every single image takes
very long. Using caTools for exporting animated gifs from 3-dimensional
arrays (dim(array)=c(900,900,No of plots) works extremely fast, but
unfortunately, the level of flexibility for plot design is very low (no
labelling, legends etc.).
I guess the problem is that levelplot() or image() first plot a full
quality image. Only on export, the quality settings from png() or jpeg()
(e.g. for resolution) become effective. How could I provide quality
settings before the time consuming plotting process starts?
Thanks a lot in advance for any kind of help!
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