# HG changeset patch
# User Pascal Lamblin <lamblinp@iro.umontreal.ca>
# Date 1243991741 14400
# Node ID 8447bc9bb2d423a0d83605a4ba3ab8055d3f7539
# Parent  6a703c5f2391494953d5ac25e1d9486da125f438# Parent  390d8c5a1fee04b81bee86dd2e0f8255571fd268
merge

diff -r 6a703c5f2391 -r 8447bc9bb2d4 pylearn/algorithms/exponential_mean.py
--- a/pylearn/algorithms/exponential_mean.py	Tue Jun 02 21:15:21 2009 -0400
+++ b/pylearn/algorithms/exponential_mean.py	Tue Jun 02 21:15:41 2009 -0400
@@ -14,6 +14,12 @@
 
     :math:`self.curval = (1.0 - (1.0/max_denom)) * self.old_curval + (1.0/max_denom) * x`
 
+
+    The symbolic buffer containing the running mean is called `old_curval`.  (This has a value
+    in the ModuleInstance).
+
+    The symbolic variable for the updated running mean is called `curval`.
+
     """
 
     max_denom = None
diff -r 6a703c5f2391 -r 8447bc9bb2d4 pylearn/algorithms/sgd.py
--- a/pylearn/algorithms/sgd.py	Tue Jun 02 21:15:21 2009 -0400
+++ b/pylearn/algorithms/sgd.py	Tue Jun 02 21:15:41 2009 -0400
@@ -4,10 +4,16 @@
 import theano
 
 class StochasticGradientDescent(theano.Module):
-    """Fixed stepsize gradient descent"""
+    """Fixed stepsize gradient descent
+
+    Methods for gradient descent are:
+    - step(arg_vals) which returns None and updates the params
+    - step_cost(arg_vals) which returns the cost value, and updates the params
+    
+    """
     def __init__(self, args, cost, params, 
                  gradients=None, stepsize=None, 
-                 updates=None, auxout=None):
+                 updates=None, auxout=None, methods=True):
         """
         :param stepsize: the step to take in (negative) gradient direction
         :type stepsize: None, scalar value, or scalar TensorVariable
@@ -15,8 +21,9 @@
         :param updates: extra symbolic updates to make when evating either step or step_cost
         (these override the gradients if necessary)
         :type updatess: dict Variable -> Variable
-        :type auxout: auxiliary outputs, list containing output symbols to 
+        :param auxout: auxiliary outputs, list containing output symbols to 
                       compute at the same time as cost (for efficiency)
+        :param methods: Should this module define the step and step_cost methods?
         """
         super(StochasticGradientDescent, self).__init__()
         self.stepsize_init = None
@@ -38,13 +45,19 @@
         if updates is not None:
             self._updates.update(updates)
 
-        auxout = auxout if auxout else []
-        self.step = theano.Method(
-                args, auxout,
-                updates=self._updates)
-        self.step_cost = theano.Method(
-                args, [cost]+auxout,
-                updates=self._updates)
+        if methods:
+            if auxout is None:
+                self.step = theano.Method(args, [], updates=self._updates)
+                self.step_cost = theano.Method(args, cost, updates=self._updates)
+            else:
+                # step cost always returns a list if auxout
+                self.step = theano.Method(
+                        args, [] + auxout,
+                        updates=self._updates)
+                self.step_cost = theano.Method(
+                        args, [cost]+auxout,
+                        updates=self._updates)
+
 
     updates = property(lambda self: self._updates.copy())
 
diff -r 6a703c5f2391 -r 8447bc9bb2d4 pylearn/external/wrap_libsvm.py
--- a/pylearn/external/wrap_libsvm.py	Tue Jun 02 21:15:21 2009 -0400
+++ b/pylearn/external/wrap_libsvm.py	Tue Jun 02 21:15:41 2009 -0400
@@ -66,7 +66,7 @@
 
 svm_problem = libsvm.svm_problem
 svm_parameter = libsvm.svm_parameter
-RBF = libsvm.svm_RBF
+RBF = libsvm.RBF
 
 
 ####################################
@@ -159,7 +159,7 @@
 def train_rbf_model(train_X, train_Y, C, gamma):
     param = libsvm.svm_parameter(C=C, kernel_type=libsvm.RBF, gamma=gamma)
     problem = libsvm.svm_problem(train_Y, train_X)
-    model libsvm.svm_model(problem, param)
+    model = svm_model(problem, param)
 
     #save_filename = state.save_filename
     #model.save(save_filename)
@@ -181,7 +181,7 @@
         train_set=None,
         svm_param=dict(kernel='RBF', C=C, gamma=g),
         save_filename='model_RBF_C%f_G%f.libsvm')
-            for C in C_grid,
+            for C in C_grid
             for g in gamma_grid]
 
     # will return quickly if jobs have already run
diff -r 6a703c5f2391 -r 8447bc9bb2d4 pylearn/io/image_tiling.py
--- a/pylearn/io/image_tiling.py	Tue Jun 02 21:15:21 2009 -0400
+++ b/pylearn/io/image_tiling.py	Tue Jun 02 21:15:41 2009 -0400
@@ -5,10 +5,10 @@
 import numpy
 from PIL import Image
 
-def scale_to_unit_interval(ndar):
+def scale_to_unit_interval(ndar,eps=1e-8):
     ndar = ndar.copy()
     ndar -= ndar.min()
-    ndar *= 1.0 / ndar.max()
+    ndar *= 1.0 / (ndar.max()+eps)
     return ndar
 
 def tile_raster_images(X, img_shape, tile_shape, tile_spacing=(0,0),