Hello, Which version of NetCDF binaries are you using?
Regards, Pascal Le 13/02/2013 10:21, Teurlai Magali a écrit :
Hi all, After reading this help post: https://stat.ethz.ch/pipermail/r-help/2011-November/297141.html I think I have the "issue in the Windows 64-bit NetCDF external dependency" and would like to know whether it is possible to fix it, or whether I should change computer to solve my problem (which could take some time, given I have a lot of files to transfer and process). Here is my problem : - I have to read a large ncdf file (3.8 gigas) - I have 20 variables in it, each variable's dimension is 250 (lon ) * 270 (lat) * 730 (time) - My computer uses windows 7 64 bit - I have installed R version 2.15.2 (64 bits) - I am using the ncdf library, the open.ncdf function works fine. - I use function get.var.ncdf to retrieve the variables. - when I read the ncdf one time step at a time, it reads ok from time steps 1 to 418 - R crashes whenever I try to read any of the variables for a time step >= 419 (no matter how much I "zoom" the spatial dimensions, and even if I try to read only one time step over a small spatial extent) with the following message : "Microsoft Visual C++ Runtime Library: This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information" On another computer (runing linux) : - ferret is able to retrieve an entire variable - matlab is able to retrieve an entire variable - R is able to retrieve an entire variable (not a problem of memory) - if we cut the ncdf to include only the 418 first time steps, the new ncdf is then... 2.0 gigas On my computer: - if I use a ncdf that has been "cut" spatially on another computer, I can extract any entire variable, over the 730 time steps (the new ncdf is then 1.8 Gigas instead of 3.8 gigas) - if I use a ncdf that keeps all the spatial information, and all the time steps, but with only one variable in it, I can read this entire variable (the new ncdf is then 800 megas) So it looks as if R were having trouble extracting variables from ncdf files of more than 2 gigas when runing under windows. - Has anyone got any explanation for this (I thought the big advantage of working wth ncdf files was the possibility to handle huge files, because R does not have to read the entire file, to read time step 419, is R putting all the previous information into memory ?) - Is there a way to fix this ? (or should I process all my files on another computer ?) Thank you in advance for all your answers. Magali _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
_______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
