I am working on dumping raster data from R into PNG files using
rasterImage(). I am working with a test matrix from the rasterImage()
example and using it to produce a PNG image with the following code:
# From the example for rasterImage(). A 3 pixel by 5 pixel b/w checkerboard.
testImage <- as.raster(0:1, nrow=3, ncol=5)
testImage
[,1] [,2] [,3] [,4] [,5]
[1,] "#000000" "#FFFFFF" "#000000" "#FFFFFF" "#000000"
[2,] "#FFFFFF" "#000000" "#FFFFFF" "#000000" "#FFFFFF"
[3,] "#000000" "#FFFFFF" "#000000" "#FFFFFF" "#000000"
png('test.png', width=5, height=3, units='px')
# Just want the image, no margins, boarders or other fancy stuff.
par(mar = c(0,0,0,0) )
plot.new()
plotArea = par('fig')
rasterImage(testImage, plotArea[1], plotArea[3],
plotArea[2], plotArea[4], interpolate = FALSE )
dev.off()
However, using R 2.12.0, 64 bit on Windows 7 I have a strange issue where
the image is shifted up by one row and to the left by one row. In other
words, the bottom row of pixels is missing along with the right column. The
code works as I expect it to on OS X and Debian.
Am I misusing the plotting commands in some way or should I submit an
off-by-one bugreport to Bugzilla?
Any suggestions or comments are most welcome.
-Charlie
-----
Charlie Sharpsteen
Undergraduate-- Environmental Resources Engineering
Humboldt State University
--
View this message in context:
http://r.789695.n4.nabble.com/Incorrect-positioning-of-raster-images-on-Windows-tp2999649p2999649.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
R-help@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.
