Merge branch 'master' of https://github.com/dmishin/tsp-solver

README.md

@@ -73,11 +73,27 @@ The triangular matrix `D` in the above example represents the following graph wi
 Square matrix may be provided, but only left triangular part is used from it.
 
 ### Utility functions
-
 *tsp_solver.util.path_cost(distance_matrix, path)*
-
 Caclulate total length of the given path, using the provided distance matrix.
 
+### Using fixed endpoints
+It is also possible to manually specify desired start and end nodes of the path. Note that this would usually increase total length of the path.
+Example, using the same distance matrix as above, but now requiring that path starts at A (index 0) and ends at C (index 2):
+
+```python
+
+D = [[],
+     [1.0],
+     [2.0, 3.0]]
+
+path = solve_tsp( D, endpoints = (0,2) )
+
+#will print path [0,1,2]
+print(path)
+```
+
+Endpoints must be different.
+
 Algorithm
 ---------
 

setup.py

@@ -3,7 +3,7 @@
 from distutils.core import setup
 
 setup(name='tsp_solver2',
-      version='0.2',
+      version='0.3',
       description='Greedy, suboptimal solver for the Travelling Salesman Problem',
       author='Dmitry Shintyakov',
       author_email='shintyakov@gmail.com',

tsp_solver/demo/numpy2svg.py

@@ -1,10 +1,13 @@
-from __future__ import with_statement, print_function
+from __future__ import print_function
 import os
 import math
 import numpy as np
 from xml.etree import ElementTree as et
-from itertools import izip
 from optparse import OptionParser
+try:
+    from itertools import izip as zip
+except ImportError:
+    pass
 
 def dbl2str( f ):
     return str(int(f))
@@ -48,7 +51,7 @@ def GenerateSVGContour(output, x,y, palette, options=None, margin=10, out_size =
     real_h = int((y1-y0)*scale + 2*margin)
 
     def xy_seq():
-        return izip(x,y)
+        return zip(x,y)
 
     # create an SVG XML element
     doc = et.Element('svg', 
@@ -71,11 +74,11 @@ def xy_seq():
                           r=circle_radius, fill='rgb(%d,%d,%d)'%palette.at(float(i)/len(x)))
 
     # ElementTree 1.2 doesn't write the SVG file header errata, so do that manually
-    with file(output, 'w') as f:
+    with open(output, 'wb') as f:
         if svg_header:
-            f.write('<?xml version=\"1.0\" standalone=\"no\"?>\n')
-            f.write('<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n')
-            f.write('\"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n')
+            f.write(b'<?xml version=\"1.0\" standalone=\"no\"?>\n')
+            f.write(b'<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n')
+            f.write(b'\"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n')
         f.write(et.tostring(doc))
 
 
@@ -152,7 +155,7 @@ def main():
     for in_file in args:
         out_file = options.output or os.path.splitext(in_file)[0]+".svg"
         try:
-            with file(in_file,"r") as fl:
+            with open(in_file,"rb") as fl:
                 xy = np.load( fl )
                 x=xy[0,:]
                 y=xy[1,:]

tsp_solver/demo/tsp.py

@@ -32,7 +32,7 @@ def spot_points( N ):
     return xy
 
 def box_points( N ):
-    xy = np.random.rand( (2,N) )
+    xy = np.random.rand(2,N)
     return xy
 
 def image_points( N, src_image ):
@@ -101,7 +101,7 @@ def main():
 
     if options.output:
         try:
-            with file( options.output, "w") as fl:
+            with open( options.output, "wb") as fl:
                 np.save( fl, xy[:,path])
                 print ("Saved file %s"%(options.output))
         except IOError as err:

tsp_solver/greedy.py

@@ -87,10 +87,10 @@ def pairs_by_dist(N, distances):
     indices = []
     for i in xrange(N):
         for j in xrange(i):
-            indices.append((i,j))
+            indices.append(i*N+j)
 
-    indices.sort(key = lambda ij: distances[ij[0]][ij[1]])
-    return indices
+    indices.sort(key = lambda ij: distances[ij//N][ij%N])
+    return ((ij//N,ij%N) for ij in indices)
 
 def solve_tsp( distances, optim_steps=3, pairs_by_dist=pairs_by_dist, endpoints=None ):
     """Given a distance matrix, finds a solution for the TSP problem.