write.matrix.csr data conversion
Dear Sam, there is C-code related to *reading* in such a file, but in the internal libsvm-format, not the matrix.csr format. There is no C-code for *writing* this to a file. There is certainly a way to speed this up, but I am not likely to do this in the near future. Best David
On 2012-11-06 19:15, Sam Steingold wrote:
David,
thanks for adding the feature.
read.matrix.csr and, especially, write.matrix.csr are extremely slow:
user system elapsed
8381.988 3810.396 12345.349
for a 2797634 x 224 matrix I have to deal with.
The help page
http://rss.acs.unt.edu/Rdoc/library/e1071/html/read.matrix.csr.html
says
David Meyer (based on C/C++-code by Chih-Chung Chang and Chih-Jen Lin)
is there any chance that you might consider replacing the R code with
the original C/C++?
Thanks a lot!
* David Meyer <qnivq.zrlre at jh.np.ng> [2012-08-27 22:57:17 +0200]: done, thanks for the suggestion. David On 2012-08-27 21:15, Sam Steingold wrote:
* jim holtman <wubygzna at tznvy.pbz> [2012-08-27 14:55:08 -0400]: Most likely when 'y' is converted to a dataframe (not sure what the function 'write.matrix.csr' does since you did not say where you got it),
sorry, library(e1071)
'0' and '1' are converted to factors which probably show up as 1 and 2 in the file.
sounds reasonable, thanks. David, could you please add an option `fac' to `write.matrix.csr', similar to `read.matrix.csr' which already accepts `fac'? thanks!
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