matrix in python

[seetha]

scalar matrix means what?how can use it?

[bvdet]

A matrix is a rectangular array of elements arranged in rows and columns. A scalar matrix is "a diagonal matrix in which all of the diagonal elements are equal" per http://www.thefreedictionary.com. A diagonal matrix is "a square matrix with all elements not on the main diagonal equal to zero". Its effect on a vector is scalar multiplication (from Wikipedia).

>>> m = Matrix(3,3)
>>> m
Matrix(3, 3)
>>> m.show()
0 0 0
0 0 0
0 0 0
>>> for i in range(3):
...     m[(i,i)]=1
...     
>>> m.show()
1 0 0
0 1 0
0 0 1
>>>