I've tried replacing numpyio with both fopen and now also npfile but I'm getting the same problem, i.e. if I write a numpy array to the file, everything else before that position in the file is now zero. It is as if it is a new file, not an existing one. Brennan Williams wrote:
I have an existing binary file containing numpy array data. It has been created using open,fwrite & close and I can read the data using fread.
I want to be able to either append a new array to the end of the file or update an existing array within the file.
I've tried opening the file with a mode of either 'ab+' or 'wb+' and then writing the data using something like....
fd = open(vfname, 'ab+') if fd: filepos=(self.id-1)*self.yarray.size*4 fd.seek(filepos) fwrite(fd, self.yarray.size, self.yarray,'f') fd.close()
When I use a mode of 'ab+' it looks like the data has been written to the file ok (no errors reported) but when I read it back I get my original data.
When I use 'wb+' then my updated data gets written and read back ok. But when I reload the file, everything apart from my updated data (i.e. everything before it in the file) is now zero.
The '+' in the mode seems to make no difference.
What am I doing wrong?
Thanks
Bren. _______________________________________________ SciPy-user mailing list SciPy-user@scipy.org http://projects.scipy.org/mailman/listinfo/scipy-user