A-M baby

Task/Matrix-multiplication/Python/matrix-multiplication-1.py

@@ -0,0 +1,38 @@
+a=((1,  1,  1,   1), # matrix A #
+     (2,  4,  8,  16),
+     (3,  9, 27,  81),
+     (4, 16, 64, 256))
+
+b=((  4  , -3  ,  4/3.,  -1/4. ), # matrix B #
+     (-13/3., 19/4., -7/3.,  11/24.),
+     (  3/2., -2.  ,  7/6.,  -1/4. ),
+     ( -1/6.,  1/4., -1/6.,   1/24.))
+
+
+
+def MatrixMul( mtx_a, mtx_b):
+    tpos_b = zip( *mtx_b)
+    rtn = [[ sum( ea*eb for ea,eb in zip(a,b)) for b in tpos_b] for a in mtx_a]
+    return rtn
+
+
+v = MatrixMul( a, b )
+
+print 'v = ('
+for r in v:
+    print '[',
+    for val in r:
+        print '%8.2f '%val,
+    print ']'
+print ')'
+
+
+u = MatrixMul(b,a)
+
+print 'u = '
+for r in u:
+    print '[',
+    for val in r:
+        print '%8.2f '%val,
+    print ']'
+print ')'

Task/Matrix-multiplication/Python/matrix-multiplication-2.py

@@ -0,0 +1,10 @@
+from operator import mul
+
+def matrixMul(m1, m2):
+  return map(
+    lambda row:
+      map(
+        lambda *column:
+          sum(map(mul, row, column)),
+        *m2),
+    m1)

Task/Matrix-multiplication/Python/matrix-multiplication-3.py

@@ -0,0 +1,2 @@
+def mm(A, B):
+    return [[sum(x * B[i][col] for i,x in enumerate(row)) for col in range(len(B[0]))] for row in A]

Task/Matrix-multiplication/Python/matrix-multiplication-4.py

@@ -0,0 +1,4 @@
+import numpy as np
+np.dot(a,b)
+#or if a is an array
+a.dot(b)