Reading a Matrix Input

A demo program for reading a matrix from a simple text file then printing it out



In [1]:

    
import numpy
numpy.set_printoptions(linewidth=95)



In [2]:

    
Filename = "matrix01.in"



In [3]:

    
F = open(Filename, "r")
# read one line from the file (a header)
hdr = F.next().split()
assert hdr[0].upper() == "MATRIX"
row, col = int(hdr[1]), int(hdr[2])
print("Matrix dimensions = %d x %d" % (row, col))









    



Matrix dimensions = 4 x 5



In [4]:

    
Mat = numpy.loadtxt(F)
F.close()



In [5]:

    
print(Mat)









    



[[  2.73400000e+01   4.51000000e+01   1.00000000e+01   0.00000000e+00  -1.41000000e+00]
 [  1.00000000e-02   2.74000000e+00   3.10000000e-01  -2.11700000e+01   8.00000000e-01]
 [  9.00000000e+00  -1.21000000e+00  -8.51000000e+00   2.10000000e-01   4.08000000e+00]
 [ -3.71000000e+01   1.54100000e+01   1.00000000e+00   2.00000000e+00   3.00000000e+00]]



In [6]:

    
print("Size of the matrix just read = %s" % (Mat.shape,))









    



Size of the matrix just read = (4, 5)