[Numpy-discussion] Fromfile Issue

Warren Weckesser warren.weckesser@enthought....
Fri Mar 9 07:33:05 CST 2012


On Fri, Mar 9, 2012 at 7:26 AM, Nicola Creati <ncreati@inogs.it> wrote:

>  Hello,
> I'm writing a library able to read LAS lidar files. I generally use it
> under Linux without any problems. I'm now testing my library on a Windows 7
> 64 bit computer and I meet some problems reading the file. I generally use
> fromfile function to read the file. I noted that the fromfile returns an
> arry with some zeros at the end if I read the whole file or if i read only
> a finite number of data i get only a fraction of them. By the way I have
> created a sample script that reproduces the problem I noted:
>
> """ Sample code """
> import numpy as np
>
> sz = 1000000
> data = np.random.random(sz)
>
> output = open('test.bin', 'w')
> data.tofile(output)
> output.close()
> del output
>
> print 'Original data:', data
>
> fid = open('test.bin', 'r')
> new_data = np.fromfile(fid)
> fid.close()
> del fid
> print 'Data read:',  new_data
>
> fid = open('test.bin', 'r')
> slice = np.fromfile(fid, count=100)
> fid.close()
> print '100 read data:',  slice
>
>
> The "new_data" array has several zeros at the end. The "slice" array has
> not 100 items. At every code run the "slice" array size changes.
>
> I'm using numpy 1.6.1 64bit (taken from Christoph Gohlke website) , with
> python 2.7.2 64 bit.
> Under Linux  Ubuntu 10.10 64bit and numpy 1.6.1 the code works as expected.
> Thanks.
>
> Nicola
>
>

Use the binary mode ('wb' and 'rb') when you open the files.

Warren


>
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion@scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.scipy.org/pipermail/numpy-discussion/attachments/20120309/edd86828/attachment.html 


More information about the NumPy-Discussion mailing list