i am using rpy2-2.0.7 (i need this to work with windows 7, and compiling the binaries for the newer rpy2 versions is a mess) to push a two-column dataframe into r, create a few layers in ggplot2, and output the image into a <.png>.
i have wasted countless hours fidgeting around with the syntax; i did manage to output the files i needed at one point, but (stupidly) did not notice and continued fidgeting around with my code ...
i would sincerely appreciate any help; below is a (trivial) example for demonstration. Thank you very much for your help!!! ~ Eric Butter
import rpy2.robjects as rob
from rpy2.robjects import r
import rpy2.rlike.container as rlc
from array import array
r.library("grDevices") # import r graphics package with rpy2
r.library("lattice")
r.library("ggplot2")
r.library("reshape")
picpath = 'foo.png'
d1 = ["cat","dog","mouse"]
d2 = array('f',[1.0,2.0,3.0])
nums = rob.RVector(d2)
name = rob.StrVector(d1)
tl = rlc.TaggedList([nums, name], tags = ('nums', 'name'))
dataf = rob.RDataFrame(tl)
## r['png'](file=picpath, width=300, height=300)
## r['ggplot'](data=dataf)+r['aes_string'](x='nums')+r['geom_bar'](fill='name')+r['stat_bin'](binwidth=0.1)
r['ggplot'](data=dataf)
r['aes_string'](x='nums')
r['geom_bar'](fill='name')
r['stat_bin'](binwidth=0.1)
r['ggsave']()
## r['dev.off']()
*The output is just a blank image (181 b).
here are a couple common errors R itself throws as I fiddle around in ggplot2:
r['png'](file=picpath, width=300, height=300)
r['ggplot']()
r['layer'](dataf, x=nums, fill=name, geom="bar")
r['geom_histogram']()
r['stat_bin'](binwidth=0.1)
r['ggsave'](file=picpath)
r['dev.off']()
*RRuntimeError: Error: No layers in plot
r['png'](file=picpath, width=300, height=300)
r['ggplot'](data=dataf)
r['aes'](geom="bar")
r['geom_bar'](x=nums, fill=name)
r['stat_bin'](binwidth=0.1)
r['ggsave'](file=picpath)
r['dev.off']()
*RRuntimeError: Error: When setting aesthetics, they may only take one value. Problems: fill,x