1 files changed, 21 insertions, 0 deletions
diff --git a/ot/gpu/cudamat/cudamat/learn.py b/ot/gpu/cudamat/cudamat/learn.py
new file mode 100644
index 0000000..741ca13
--- /dev/null
+++ b/ot/gpu/cudamat/cudamat/learn.py
@@ -0,0 +1,21 @@
+import os
+
+import ctypes as ct
+import numpy as np
+
+from cudamat import load_library, generate_exception
+
+_cudalearn = load_library('libcudalearn')
+
+_cudalearn.mult_by_sigmoid_deriv.restype = ct.c_int
+
+def mult_by_sigmoid_deriv(target, acts):
+    """
+    target = target * acts * (1 - acts)
+
+    Useful for doing backprop in neural networks with logistic units.
+    """
+
+    err_code = _cudalearn.mult_by_sigmoid_deriv(target.p_mat, acts.p_mat)
+    if err_code:
+        raise generate_exception(err_code)