Script for quantizing weights.

Use smaller precision to store the weights to decrease the file size.

See discussion in issue #1733.

Pull request #1736.

training/tf/quantize_weights.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+import sys, os, argparse
+
+def format_n(x):
+    x = float(x)
+    x = '{:.3g}'.format(x)
+    x = x.replace('e-0', 'e-')
+    if x.startswith('0.'):
+        x = x[1:]
+    if x.startswith('-0.'):
+        x = '-' + x[2:]
+    return x
+
+if __name__ == "__main__":
+
+    parser = argparse.ArgumentParser(
+            description='Quantize network file to decrease the file size.')
+    parser.add_argument("input",
+        help='Input file', type=str)
+
+    parser.add_argument("-o", "--output",
+        help='Output file. Defaults to input + "_quantized"',
+        required=False, type=str, default=None)
+
+    args = parser.parse_args()
+
+    if args.output == None:
+        output_name = os.path.splitext(sys.argv[1])
+        output_name = output_name[0] + '_quantized' + output_name[1]
+    else:
+        output_name = args.output
+    output = open(output_name, 'w')
+
+    calculate_error = True
+    error = 0
+
+    with open(args.input, 'r') as f:
+        for line in f:
+            line = line.split(' ')
+            lineq = list(map(format_n, line))
+
+            if calculate_error:
+                e = sum((float(line[i]) - float(lineq[i]))**2 for i in range(len(line)))
+                error += e/len(line)
+            output.write(' '.join(lineq) + '\n')
+
+    if calculate_error:
+        print('Weight file difference L2-norm: {}'.format(error**0.5))
+
+    output.close()