[R] Matrix library, CHOLMOD error: problem too large

Duncan Murdoch murdoch at stats.uwo.ca
Fri Jun 22 20:04:03 CEST 2007


On 6/22/2007 1:26 PM, Jose Quesada wrote:
> I have a pretty large sparse matrix of integers:
>> dim(tasa)
> [1] 91650 37651
> 
> I need to add one to it in order to take logs, but I'm getting the  
> following error:
> 
>> tasa  = log(tasa + 1)
> CHOLMOD error: problem too large
> Error in asMethod(object) : Cholmod error `problem too large'
> 
> I have 2 Gb of RAM, and the current workspace is barely 300mb.
> Is there any workaround to this? Anyone has any experience with this error?
>

If tasa is sparse, then tasa+1 will not be sparse, so that's likely your 
problem.  You might have better luck with

log1p(tasa)

if the authors of the Matrix package have written a method for log1p(); 
if not, you'll probably have to do it yourself.

Duncan Murdoch



More information about the R-help mailing list