You indicate that you are reading from a file. The thread you reference was about copying data in memory. I’d think matters of buffering and read-ahead caches would be far more relevant than anything else. Am I missing something?
> On Oct 26, 2014, at 5:18 AM, Nikhil Garg <nikhilgarg....@gmail.com> wrote: > > > Hi, > > I have looked at the following thread to copy a c# array to numpy list using > python dot net. > > https://mail.python.org/pipermail/pythondotnet/2014-May/001525.html > <https://mail.python.org/pipermail/pythondotnet/2014-May/001525.html> > > When I try the methods mentioned in the complete thread I manage to get the > array from simple iteration method or > np.fromiter, but I have not been able to make GCHandle or Marshal.Copy work > for my case. > > To explain about my issue, I use a computer code written in c# which produces > output in a custom build format. I am able to access the data from the file > system using python dot net, but it seems that it take almost half an hour to > get the data from the file. > > For example my file has an array of size 5018x73x400, if i use fromiter, i > provide the last bit of array to copy to python due to the way file stores > output. > > for j in xrange(num_nodes-1): > for i in xrange(nsteps): > temp = file_in.ReadItemTimeStep(j+1,i).Data > temp_1 = np.fromiter(temp, float) > dest[j, i] = temp_1 > > Other way of doing same task would be to use a for loop but tht would be > really slow. > > for k in xrange(num_nodes-1): > for k in xrange(nsteps): > for i in xrange(nvals): > temp[k,j,i] = file_in.ReadItemTimeStep(k+1, j).Data[i] > > I am trying to find a faster way to extract the data from the file. I was > wondering if there is a possibility to use something like GChandle or > Marshal.Copy. I have also attached same output from Marshal.Copy > > Marshal.Copy(temp, 0, > IntPtr.__overloads__[int](temp2.__array_interface__['data'][0]), len(temp)) > > > 0.00000000e+000, 0.00000000e+000, 0.00000000e+000, > 0.00000000e+000, 3.13551399e-242, 4.20993645e-161, > 8.71245319e-119, 8.38370432e-089, 2.60762781e-075, > 1.92616374e-072, 2.89006184e-072, 3.06007265e-082, > 3.81879776e-315, 0.00000000e+000, 0.00000000e+000, > 0.00000000e+000, 1.03959661e-297, 7.22038448e-196, > 3.05237954e-130, 2.58469346e-093, 2.29495911e-070, > 3.74354820e-062, 1.74288060e-061, 2.13172553e-067, > 2.74305386e-077, 0.00000000e+000, 0.00000000e+000, > 0.00000000e+000, 0.00000000e+000, 1.02484756e-240, > 1.70193770e-154, 1.30625320e-108, 1.16793762e-075, > 2.96889340e-061, 7.84687103e-058, 1.16879604e-057, > 5.56256478e-068, 4.06437857e-315, 0.00000000e+000, > 0.00000000e+000, 0.00000000e+000, 1.11705239e-296, > 1.46978156e-194, 1.98034372e-128, 3.79615170e-091, > 5.88936509e-068, 1.85305929e-059, 2.16186001e-058, > > Whereas the actual values stored in the array are > 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, > 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, > 0.00000000e+00, 0.00000000e+00, 5.66641200e-37, > 1.24961600e-30, 5.34846800e-25, 1.72519600e-20, > 1.49402200e-17, 3.27685300e-15, 4.10687500e-13, > 1.87978200e-11, 2.01397900e-10, 8.83561100e-10, > 2.14397600e-09, 2.02600300e-09, 2.47599800e-09, > 2.15987100e-09, 4.82694100e-10, 1.18759300e-10, > 3.32024100e-11, 0.00000000e+00, 0.00000000e+00, > 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, > 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, > 1.45288600e-37, 7.37245900e-31, 7.59282500e-25, > 5.85463400e-20, 1.20634700e-16, 3.06414300e-14, > 5.16041300e-12, 2.87562800e-10, 3.62841500e-09, > 1.63540600e-08, 4.06988300e-08, 3.97764200e-08, > 4.88768500e-08, 4.07385000e-08, 8.78868600e-09, > > I would appreciate any help i can get regarding this matter. > > Nikhil > _________________________________________________ > Python.NET mailing list - PythonDotNet@python.org > https://mail.python.org/mailman/listinfo/pythondotnet
_________________________________________________ Python.NET mailing list - PythonDotNet@python.org https://mail.python.org/mailman/listinfo/pythondotnet
