Add numpy.block snippet (#539)

snippets/numpy/lib/__init__.py

@@ -1,4 +1,5 @@
 
 from .function_base import *
 from .polynomial import *
-from .type_check import *
+from .type_check import *
+from .block import *

snippets/numpy/lib/block.py

@@ -0,0 +1,17 @@
+from ulab.numpy import zeros
+
+def block(S):
+    w = sum([len(m[0]) for m in S[0]])
+    h = sum([len(row[0]) for row in S])
+    M = zeros((h, w))
+    i = 0
+    j = 0
+    for row in S:
+        di = len(row[0])
+        for matrix in row:
+            dj = len(matrix[0])
+            M[i:i + di, j:j + dj] = matrix
+            j += dj
+        i += di
+        j = 0
+    return M

snippets/tests/numpy/lib/block.py

@@ -0,0 +1,19 @@
+from ulab.numpy import array, zeros, eye, ones
+from snippets import numpy
+
+a = array([[1, 1]])
+b = array([[2]])
+c = array(
+    [[3, 3],
+     [3, 3],
+     [3, 3]])
+d = array(
+    [[4],
+     [4],
+     [4]])
+print(numpy.block([[a, b], [c, d]]))
+a = zeros((2, 3))
+b = eye(2) * 2
+c = eye(3) * 5
+d = ones((3, 2))
+print(numpy.block([[a, b], [c, d]]))

snippets/tests/numpy/lib/block.py.exp

@@ -0,0 +1,9 @@
+array([[1, 1, 2],
+       [3, 3, 4],
+       [3, 3, 4],
+       [3, 3, 4]])
+array([[0, 0, 0, 2, 0],
+       [0, 0, 0, 0, 2],
+       [5, 0, 0, 1, 1],
+       [0, 5, 0, 1, 1],
+       [0, 0, 5, 1, 1]])