Refactor iteration.

common.py

@@ -52,6 +52,28 @@ def dumps(sym, n=1):
 def norm(x):
     return np.sqrt(np.dot(x.conj(), x).real)
 
+
+def iterate(data, bufsize, offset=0, advance=1, func=None):
+    assert bufsize > 0
+    assert offset >= 0
+    assert advance > 0
+    buf = np.zeros(bufsize)
+    buf_index = 0
+    for data_index, value in enumerate(data):
+        if data_index < offset:
+            continue
+
+        buf[buf_index] = value
+        buf_index += 1
+
+        if buf_index == bufsize:
+            result = func(buf) if func else buf
+            print offset, result
+            yield offset, result
+            buf[:-advance] = buf[advance:]
+            buf_index = max(0, buf_index - advance)
+            offset += advance
+
 if __name__ == '__main__':
 
     import pylab