On Mon, Dec 12, 2011 at 2:19 AM, tony333 <tony33...@hotmail.com> wrote:
> i use library(ncdf) to read this file as follow > library(ncdf) > sst.nc = open.ncdf(title) > lonall = get.var.ncdf(sst.nc,'lon') > latall = get.var.ncdf(sst.nc,'lat') > precip = get.var.ncdf(sst.nc,'pre') > close(sst.nc) > if i use this method my pc freeze and not respond until i restart it is > there > As Paul already mentioned, more information would be useful, but here's a suggestion. If you have a data set that is too big to fit in your computer's memory, read it in one timestep at a time and process that timestep. For example, you could get the number of timesteps in the variable like this: varname = 'pre' sst.nc = open.ncdf(file) varsize = sst.nc$var[[varname]]$size nt = dim( varsize )[3] Then read in one timestep at a time and process it: for( itstep in 1:nt ) { data = get.var.ncdf( sst.nc, varname, start=c(1,1,itstep), count=c(-1,-1,1)) ...process one timestep of the data here ... } Regards, --Dave -- Dr. David W. Pierce Division of Climate, Atmospheric Science, and Physical Oceanography Scripps Institution of Oceanography, La Jolla, California, USA (858) 534-8276 (voice) / (858) 534-8561 (fax) dpie...@ucsd.edu [[alternative HTML version deleted]] ______________________________________________ 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.