Merge branch 'master' of https://github.com/openai/baselines into peterz_import_internal

baselines/common/tile_images.py

@@ -0,0 +1,23 @@
+import numpy as np
+
+def tile_images(img_nhwc):
+    """
+    Tile N images into one big PxQ image
+    (P,Q) are chosen to be as close as possible, and if N
+    is square, then P=Q.
+
+    input: img_nhwc, list or array of images, ndim=4 once turned into array
+        n = batch index, h = height, w = width, c = channel
+    returns:
+        bigim_HWc, ndarray with ndim=3
+    """
+    img_nhwc = np.asarray(img_nhwc)
+    N, h, w, c = img_nhwc.shape
+    H = int(np.ceil(np.sqrt(N)))
+    W = int(np.ceil(float(N)/H))
+    img_nhwc = np.array(list(img_nhwc) + [img_nhwc[0]*0 for _ in range(N, H*W)])
+    img_HWhwc = img_nhwc.reshape(H, W, h, w, c)
+    img_HhWwc = img_HWhwc.transpose(0, 2, 1, 3, 4)
+    img_Hh_Ww_c = img_HhWwc.reshape(H*h, W*w, c)
+    return img_Hh_Ww_c
+