Add tool path optimization example

Add example demonstrating use of tsp-solver with pcb-tools to optimize
tool paths in an excellon file. This is based on @koppi's script in #30

1 files changed, 90 insertions, 0 deletions

diff --git a/examples/excellon_optimize.py b/examples/excellon_optimize.py
new file mode 100644
index 0000000..5f0adbc
--- /dev/null
+++ b/examples/excellon_optimize.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Example using pcb-tools with tsp-solver (github.com/dmishin/tsp-solver) to
+# optimize tool paths in an Excellon file.
+#
+#
+# Copyright 2015 Hamilton Kibbe <ham@hamiltonkib.be>
+# Based on a script by https://github.com/koppi
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+import sys
+import math
+import gerber
+from operator import sub
+from gerber.excellon import DrillHit
+
+try:
+    from tsp_solver.greedy import solve_tsp
+except ImportError:
+    print('\n=================================================================\n'
+          'This example requires tsp-solver be installed in order to run.\n\n'
+          'tsp-solver can be downloaded from:\n'
+          '    http://github.com/dmishin/tsp-solver.\n'
+          '=================================================================')
+    sys.exit(0)
+
+
+if __name__ == '__main__':
+
+    # Get file name to open
+    if len(sys.argv) < 2:
+        fname = 'gerbers/shld.drd'
+    else:
+        fname = sys.argv[1]
+
+    # Read the excellon file
+    f = gerber.read(fname)
+
+    positions   = {}
+    tools   = {}
+    hit_counts = f.hit_count()
+    oldpath = sum(f.path_length().values())
+
+    #Get hit positions
+    for hit in f.hits:
+        tool_num = hit.tool.number
+        if tool_num not in positions.keys():
+            positions[tool_num]   = []
+        positions[tool_num].append(hit.position)
+
+    hits = []
+
+    # Optimize tool path for each tool
+    for tool, count in iter(hit_counts.items()):
+
+        # Calculate distance matrix
+        distance_matrix = [[math.hypot(*tuple(map(sub, 
+                                                  positions[tool][i], 
+                                                  positions[tool][j]))) 
+                            for j in iter(range(count))] 
+                            for i in iter(range(count))]
+
+        # Calculate new path
+        path = solve_tsp(distance_matrix, 50)
+
+        # Create new hits list
+        hits += [DrillHit(f.tools[tool], positions[tool][p]) for p in path]
+
+    # Update the file
+    f.hits = hits
+    f.filename = f.filename + '.optimized'
+    f.write()
+    
+    # Print drill report
+    print(f.report())
+    print('Original path length:  %1.4f' % oldpath)
+    print('Optimized path length: %1.4f' % sum(f.path_length().values()))
+