Bug fixing samplers / rendering engine. The changes in the rendering are not backwards compatible.

1 files changed, 104 insertions, 0 deletions

diff --git a/ep_sampler_centeredwalk.py b/ep_sampler_centeredwalk.py
new file mode 100644
index 0000000..6f48e4a
--- /dev/null
+++ b/ep_sampler_centeredwalk.py
@@ -0,0 +1,104 @@
+# coding: UTF-8
+# Copyright 2009, 2010 Thomas Jourdan
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+import ka_utils
+
+import model_locus
+import model_random
+import model_constraintpool
+import ep_sampler_randomwalk
+from gettext import gettext as _
+
+SECTIONS_CONSTRAINT = 'sectionsconstraint'
+
+class CenteredWalkSampler(ep_sampler_randomwalk.RandomWalkSampler):
+    """CenteredWalkSampler: 
+    inv: len(self.direction_steps) > 0
+    """
+
+    cdef = [{'bind'  : SECTIONS_CONSTRAINT,
+             'name'  : 'Number of sections.',
+             'domain': model_constraintpool.INT_RANGE,
+             'min'   : 1, 'max': 100},
+           ]
+
+    def __init__(self, trunk):
+        """Constructor for a random walk."""
+        super(CenteredWalkSampler, self).__init__(trunk)
+
+    def __eq__(self, other):
+        """Equality."""
+        equal = isinstance(other, CenteredWalkSampler) \
+                and super(CenteredWalkSampler, self).__eq__(other)
+        return equal
+
+    def crossingover(self, other):
+        """
+        pre: isinstance(other, CenteredWalkSampler)
+        pre: isinstance(self, CenteredWalkSampler)
+        # check for distinct references, needs to copy content, not references
+        post: __return__ is not self
+        post: __return__ is not other
+        post: model_locus.unique_check(__return__, self, other) == ''
+        """
+        new_one = CenteredWalkSampler(self.get_trunk())
+        new_one.direction_steps = model_random.crossingover_list(self.direction_steps,
+                                                              other.direction_steps)
+        return new_one
+
+    @staticmethod
+    def _numeric_compare(point1, point2):
+        """Comparison function based on Euklidian distance from center 0.0."""
+        diff1 = point1[0]*point1[0] + point1[1]*point1[1]
+        diff2 = point2[0]*point2[0] + point2[1]*point2[1]
+        if diff1 > diff2:
+            return 1
+        elif diff1 < diff2:
+            return -1
+        return 0
+
+    def get_sample_points(self):
+        """ Produces a list of sampling points.
+        The points describes an random walk starting near (0.5, 0.5).
+        """
+        sample_points = []
+#        sample_points.append( (0.0, 0.0) )
+#        return sample_points
+        sample_points = super(CenteredWalkSampler, self).get_sample_points()
+        sample_points.sort(cmp=CenteredWalkSampler._numeric_compare,
+                           reverse=False)
+        return sample_points
+
+    def explain(self):
+        """
+        post: len(__return__) == 3
+        """
+        head = _('Centered random walk sampler: %d points') \
+                                            % (len(self.direction_steps))
+        description = ka_utils.explain_points(head, self.get_sample_points())
+        return description, \
+               None, \
+               None
+
+    def copy(self):
+        """A copy constructor.
+        post: isinstance(__return__, CenteredWalkSampler)
+        # check for distinct references, needs to copy content, not references
+        post: __return__ is not self
+        """
+        new_one = CenteredWalkSampler(self.get_trunk())
+        new_one.direction_steps = model_random.copy_list(self.direction_steps)
+        return new_one