Extracting matrix from a text file

[telekab1]

Hello to all!!

I am new in python, and I am running it on Mac with Smultron editor. I
need to read a textfile that includes numbers (in a matrix form),
indexes, and strings, like this:

Marsyas-kea distance matrix for MIREX 2007 Audio Similarity Exchange
Q/R 1 2 3
4 5
1 0 4.54592 4.36685
5.29463 3.85728
2 4.54592 0 3.97667
5.02151 4.64284
3 4.36685 3.97667 0
4.98743 4.83683
4 5.29463 5.02151 4.98743
0 6.04393
5 3.85728 4.64284 4.83683 6.04393 0

My code to get this information is:

matrix = open("dmatrix_5.txt");

while 1:
mat = matrix.readline()
if not mat:
break
pass # do something
print mat



So I just want to keep the matrix in the "middle" for math
computations.

0 4.54592 4.36685
5.29463 3.85728
4.54592 0 3.97667
5.02151 4.64284
4.36685 3.97667 0
4.98743 4.83683
5.29463 5.02151 4.98743
0 6.04393
3.85728 4.64284 4.83683 6.04393 0


I've seen and tried a lot of ways, like split or isinstance.. but
never get the wanted result.... does anyone have an idea, or hint?
Thank you once more for your help!

Best Regards,
Bea

 

[Mark Lawrence]

Hello to all!!

I am new in python, and I am running it on Mac with Smultron editor. I
need to read a textfile that includes numbers (in a matrix form),
indexes, and strings, like this:

Marsyas-kea distance matrix for MIREX 2007 Audio Similarity Exchange
Q/R 1 2 3
4 5
1 0 4.54592 4.36685
5.29463 3.85728
2 4.54592 0 3.97667
5.02151 4.64284
3 4.36685 3.97667 0
4.98743 4.83683
4 5.29463 5.02151 4.98743
0 6.04393
5 3.85728 4.64284 4.83683 6.04393 0

My code to get this information is:

matrix = open("dmatrix_5.txt");

while 1:
mat = matrix.readline()
if not mat:
break
pass # do something
print mat



So I just want to keep the matrix in the "middle" for math
computations.

0 4.54592 4.36685
5.29463 3.85728
4.54592 0 3.97667
5.02151 4.64284
4.36685 3.97667 0
4.98743 4.83683
5.29463 5.02151 4.98743
0 6.04393
3.85728 4.64284 4.83683 6.04393 0


I've seen and tried a lot of ways, like split or isinstance.. but
never get the wanted result.... does anyone have an idea, or hint?
Thank you once more for your help!

Best Regards,
Bea

I think your best bet is to read and action the responses you got to
your original email from three days ago. If these have got lost in the
post simply search online, they're bound to be archived somewhere.

 

[Colin J. Williams]

Hello to all!!

I am new in python, and I am running it on Mac with Smultron editor. I
need to read a textfile that includes numbers (in a matrix form),
indexes, and strings, like this:

Marsyas-kea distance matrix for MIREX 2007 Audio Similarity Exchange
Q/R 1 2 3
4 5
1 0 4.54592 4.36685
5.29463 3.85728
2 4.54592 0 3.97667
5.02151 4.64284
3 4.36685 3.97667 0
4.98743 4.83683
4 5.29463 5.02151 4.98743
0 6.04393
5 3.85728 4.64284 4.83683 6.04393 0

My code to get this information is:

matrix = open("dmatrix_5.txt");

while 1:
mat = matrix.readline()
if not mat:
break
pass # do something
print mat



So I just want to keep the matrix in the "middle" for math
computations.

0 4.54592 4.36685
5.29463 3.85728
4.54592 0 3.97667
5.02151 4.64284
4.36685 3.97667 0
4.98743 4.83683
5.29463 5.02151 4.98743
0 6.04393
3.85728 4.64284 4.83683 6.04393 0


I've seen and tried a lot of ways, like split or isinstance.. but
never get the wanted result.... does anyone have an idea, or hint?
Thank you once more for your help!

Best Regards,
Bea

numpy provides an answer. See the little script below:

import numpy as _n
import string as _s
a= "0 4.54592 4.36685 5.29463 3.85728 " + \
"4.54592 0 3.97667 5.02151 4.64284 " + \
'4.36685 3.97667 0 4.98743 4.83683 ' + \
'5.29463 5.02151 4.98743 0 6.04393 ' + \
'3.85728 4.64284 4.83683 6.04393 0'

d= _n.mat(_n.reshape(_n.array(a.split(), dtype= _n.float), (5, 5)))
print repr(d)
print 'Default printoptions:', _n.get_printoptions()

for p in range(9):
_n.set_printoptions(precision= p)
print 'precision= ', p, '\n', d

When you run this, you'll see that there is a numpy glitch for precisions > 5.

Colin W.