>>> import matrius
>>> m = matrius.MatriuDispersa(2,2)
>>> m.nfils, m.ncols
(2, 2)
>>> m[2,2] = 3.5
>>> len(m)
1
>>> print("%.1f" % m[2,2])
3.5
>>> print("%.1f" % m[1,2])
0.0
>>> print("%.1f" % m[0,0])
Traceback (most recent call last):
  ... 
IndexError
>>> print("%.1f" % m[0,2])
Traceback (most recent call last):
  ... 
IndexError
>>> m[0,2] = 3.5
Traceback (most recent call last):
  ... 
IndexError
>>> len(m)
1
>>> m[3,2] = 3.5
Traceback (most recent call last):
  ... 
IndexError
>>> len(m)
1
>>> m[3,4] = 3.5
Traceback (most recent call last):
  ... 
IndexError
>>> len(m)
1
>>> m[1,4] = 3.5
Traceback (most recent call last):
  ... 
IndexError
>>> len(m)
1
>>> m[1,1] = 2.5
>>> len(m)
2
>>> print("%.1f" % m[2,2])
3.5
>>> print("%.1f" % m[1,2])
0.0
>>> print("%.1f" % m[1,1])
2.5
>>> print("%.1f" % m[2,1])
0.0
>>> print("%.1f" % m[0,1])
Traceback (most recent call last):
  ... 
IndexError
>>> print("%.1f" % m[0,0])
Traceback (most recent call last):
  ... 
IndexError
>>> m[1,1] = 0.0
>>> len(m)
1
>>> m[2,2] = 0.0
>>> len(m)
0
>>> m = matrius.MatriuDispersa()
>>> str(m) == ''
True
>>> m = matrius.MatriuDispersa(2,2)
>>> str(m) == '0.0 0.0\n0.0 0.0'
True
>>> print(m)
0.0 0.0
0.0 0.0
>>> m[2,2] = 1.0
>>> m[1,1] = 1.0
>>> print(m)
1.0 0.0
0.0 1.0
>>> m1 = matrius.MatriuDispersa(3,2)
>>> m1[1,1] = 1.0
>>> m1[1,2] = 3.0
>>> m1[2,1] = 1.0
>>> m1[3,1] = 1.0
>>> m1[3,2] = 2.0
>>> print(m1)
1.0 3.0
1.0 0.0
1.0 2.0
>>> m2 = matrius.MatriuDispersa(3,2)
>>> m2[2,1] = 7.0
>>> m2[2,2] = 5.0
>>> m2[3,1] = 2.0
>>> m2[3,2] = 1.0
>>> print(m2)
0.0 0.0
7.0 5.0
2.0 1.0
>>> mA = matrius.MatriuDispersa(3,3)
>>> mA[1,1] = 2.0
>>> mA[1,3] = 1.0
>>> mA[2,1] = 3.0
>>> mA[3,1] = 5.0
>>> mA[3,2] = 1.0
>>> mA[3,3] = 1.0
>>> mB = matrius.MatriuDispersa(3,3)
>>> mB[1,1] = 1.0
>>> mB[1,3] = 1.0
>>> mB[2,1] = 1.0
>>> mB[2,2] = 2.0
>>> mB[2,3] = 1.0
>>> mB[3,1] = 1.0
>>> mB[3,2] = 1.0
>>> print(mA + mB)
3.0 0.0 2.0
4.0 2.0 1.0
6.0 2.0 1.0
>>> print(mA + mA)
4.0 0.0 2.0
6.0 0.0 0.0
10.0 2.0 2.0
>>> print(mA * mB)
3.0 1.0 2.0
3.0 0.0 3.0
7.0 3.0 6.0
>>> print(mB * mA)
7.0 1.0 2.0
13.0 1.0 2.0
5.0 0.0 1.0
>>> print(2.5 * mA)
5.0 0.0 2.5
7.5 0.0 0.0
12.5 2.5 2.5
>>> print(-1 * mB)
-1.0 0.0 -1.0
-1.0 -2.0 -1.0
-1.0 -1.0 0.0
>>> m = matrius.identitat(3)
>>> len(m)
3
>>> print(1.0 *m)
1.0 0.0 0.0
0.0 1.0 0.0
0.0 0.0 1.0
>>> print(mA * m)
2.0 0.0 1.0
3.0 0.0 0.0
5.0 1.0 1.0