# HG changeset patch
# User James Bergstra <bergstrj@iro.umontreal.ca>
# Date 1255709045 14400
# Node ID 67b92a42f86b95722f3346a381e8b12a871195c8
# Parent  43e726898cf9f850270b71cd1aed55e9af1ff632
added dataset_ops

diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/COIL100.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/COIL100.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,62 @@
+
+"""
+http://www1.cs.columbia.edu/CAVE/software/softlib/coil-100.php
+
+"Columbia Object Image Library (COIL-100),"
+    S. A. Nene, S. K. Nayar and H. Murase, 
+        Technical Report CUCS-006-96, February 1996. 
+
+"""
+
+import os, cPickle
+import Image, numpy
+from pylearn.datasets.config import data_root # config
+
+from .memo import memo
+
+def filenames():
+    root = os.path.join(data_root(), 'COIL-100', 'coil-100', )
+    for filename in os.listdir(root):
+        yield filename, os.path.join(root,filename )
+
+def filenameidx_imgidx(filename):
+    if filename.startswith("obj"):
+        obj_idx = int(filename[3:filename.index("_")])
+        img_idx = int(filename[filename.index("_")+2:filename.index(".")])
+        return obj_idx, img_idx
+    else:
+        raise ValueError(filename)
+
+_32x32grey_path = os.path.join(data_root(), "COIL-100", "dct_32x32_grey.pkl")
+_32x32grey_header = "Dictionary of COIL-100 dataset at 32x32 resolution, greyscale"
+def build_32x32_grey():
+    f = file(_32x32grey_path, "w")
+    cPickle.dump(_32x32grey_header, f, protocol=cPickle.HIGHEST_PROTOCOL)
+
+    dct = {}
+    for filename, fullname in filenames():
+        if filename.startswith('obj'):
+            obj_idx, img_idx = filenameidx_imgidx(filename)
+            img = numpy.asarray(Image.open(fullname))
+            dct.setdefault(obj_idx, {})[img_idx] = img.mean(axis=2)[::4,::4]
+    rval = numpy.empty((100, 72, 32, 32), dtype='float32')
+    rval[...] = -1
+    for obj_id, dd in dct.iteritems():
+        for img_id, v in dd.iteritems():
+            rval[obj_id, img_id, :, :] = v
+    assert numpy.all(rval >= 0.0)
+
+    cPickle.dump(rval, f, protocol=cPickle.HIGHEST_PROTOCOL)
+    f.close()
+
+@memo
+def get_32x32_grey():
+    f = file(_path_32x32_grey)
+    if _32x32grey_header != cPickle.load(f):
+        raise ValueError('wrong pickle file')
+    rval = cPickle.load(f)
+    f.close()
+    return rval
+
+
+
diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/MNIST.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/MNIST.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,126 @@
+"""Regular MNIST using the dataset protocol
+"""
+import os, numpy
+import theano
+from pylearn.datasets.config import data_root # config
+from pylearn.io.ubyte import read_ubyte_matrix
+from protocol import TensorFnDataset # protocol.py __init__.py
+from .memo import memo
+
+@memo
+def get_train_img_u8_rasterized():
+    """Returns 60000 x 784 MNIST train set"""
+    return read_ubyte_matrix(
+            os.path.join(data_root(), 'mnist', 'train-images-idx3-ubyte'),
+            60000, 784, 16,
+            write=False, align=True, as_dtype='uint8')
+@memo
+def get_test_img_u8_rasterized():
+    """Returns 10000 x 784 MNIST test set"""
+    return read_ubyte_matrix(
+            os.path.join(data_root(), 'mnist', 't10k-images-idx3-ubyte'),
+            10000, 784, 16,
+            write=False, align=True, as_dtype='uint8')
+@memo
+def get_train_labels():
+    # these are actually uint8, but the nnet classif code is for ints.
+    return read_ubyte_matrix(
+            os.path.join(data_root(), 'mnist', 'train-labels-idx1-ubyte'),
+            60000, 1, 8,
+            write=False, align=True, as_dtype='int32').reshape(60000)
+@memo
+def get_test_labels():
+    # these are actually uint8, but the nnet classif code is for ints.
+    return read_ubyte_matrix(
+            os.path.join(data_root(), 'mnist', 't10k-labels-idx1-ubyte'),
+            10000, 1, 8,
+            write=False, align=True, as_dtype='int32').reshape(10000)
+
+#This will cause both the uint8 version and the float version of the dataset to be cached.
+# For larger datasets, it would be better to use Theano's cast(x, dtype) to do this conversion
+# on the fly.
+@memo
+def get_train_img_f32_rasterized():
+    return get_train_img_u8_rasterized() / numpy.asarray(255, dtype='float32')
+@memo
+def get_train_img_f64_rasterized():
+    return get_train_img_u8_rasterized() / numpy.asarray(255, dtype='float64')
+@memo
+def get_test_img_f32_rasterized():
+    return get_test_img_u8_rasterized() / numpy.asarray(255, dtype='float32')
+@memo
+def get_test_img_f64_rasterized():
+    return get_test_img_u8_rasterized() / numpy.asarray(255, dtype='float64')
+
+#@constructor
+def mnist(s_idx, split, dtype='float64', rasterized=False):
+    """
+    :param s_idx:
+
+    :param split:
+
+    :param dtype:
+
+    :param rasterized: return examples as vectors (True) or 28x28 matrices (False)
+
+    """
+    if split not in ('train', 'valid', 'test'):
+        raise ValueError('split should be train, valid, or test', split)
+
+    if split == 'test':
+        l_fn = get_test_labels
+        if dtype == 'uint8':
+            i_fn = get_test_img_u8_rasterized
+        elif dtype == 'float32':
+            i_fn = get_test_img_f32_rasterized
+        elif dtype == 'float64':
+            i_fn = get_test_img_f64_rasterized
+        else:
+            raise ValueError('invalid dtype', dtype)
+    else:
+        l_fn = get_train_labels
+        if dtype == 'uint8':
+            i_fn = get_train_img_u8_rasterized
+        elif dtype == 'float32':
+            i_fn = get_train_img_f32_rasterized
+        elif dtype == 'float64':
+            i_fn = get_train_img_f64_rasterized
+        else:
+            raise ValueError('invalid dtype', dtype)
+
+    if split == 'test':
+        idx = s_idx
+    elif split == 'train':
+        idx = s_idx % 50000
+    else: #valid
+        idx = s_idx + 50000
+
+    x = TensorFnDataset(dtype, (False,), i_fn, (784,))(idx)
+    y = TensorFnDataset('int32', (), l_fn)(idx)
+    if x.ndim == 1:
+        if not rasterized:
+            x = x.reshape((28,28))
+    elif x.ndim == 2:
+        if not rasterized:
+            x = x.reshape(x.shape[0], (28,28))
+    else:
+        assert False, 'what happened?'
+
+    return x, y
+nclasses = 10
+
+def glviewer(part='train'):
+    from glviewer import GlViewer
+    if part == 'train':
+        if 0:
+            #hack that doesn't use the op
+            x = get_train_img_u8_rasterized().reshape((60000, 28, 28))
+            GlViewer(x.__getitem__).main()
+        else:
+            # test that uses the op
+            i = theano.tensor.iscalar()
+            f = theano.function([i], mnist(i, 'train', dtype='uint8', rasterized=False))
+            GlViewer(f).main()
+
+
+
diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/README.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/README.txt	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,13 @@
+The dataset_ops folder contains Theano Ops that provide dataset access to theano
+programs.
+
+The protocol.py file sets out the basic convention that is followed by the Ops
+in the other files.
+
+For an example of how to set up a dataset whose elements are slices from some
+big underlying tensor, see MNIST.py.
+
+For an example of how to set up a dynamically-generated dataset, see
+gldataset.py.
+
+
diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/__init__.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/__init__.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,4 @@
+import logging
+logging.getLogger('dataset_ops').setLevel(logging.INFO)
+
+from protocol import Dataset, TensorDataset, TensorFnDataset  # protocol.py
diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/gldataset.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/gldataset.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,490 @@
+"""Demonstrate a complicated dynamically-generated dataset.
+"""
+
+# __init__.py
+
+import sys, copy, logging, sys
+
+import Image #PIL
+
+from OpenGL.GL import *
+from OpenGL.GLU import *
+from OpenGL.GLUT import *
+from pyglew import *
+
+from glviewer import load_texture
+
+import numpy
+
+import theano
+from theano.compile.sandbox import shared
+from theano.compile.sandbox import pfunc as function
+
+_logger = logging.getLogger('gldataset')
+def debug(*msg): _logger.debug(' '.join(str(m) for m in msg))
+def info(*msg): _logger.info(' '.join(str(m) for m in msg))
+def warn(*msg): _logger.warn(' '.join(str(m) for m in msg))
+def warning(*msg): _logger.warning(' '.join(str(m) for m in msg))
+def error(*msg): _logger.error(' '.join(str(m) for m in msg))
+
+def init_GL(shape=(64,64), title='Offscreen rendering using FB0'):
+    if not init_GL.done:
+        w, h = shape
+        init_GL.done = True
+        info('initializing OpenGl subsystem')
+        glutInit (sys.argv)
+        glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH)
+        glutInitWindowSize (w,h)
+        init_GL.window = glutCreateWindow (title)
+        glewInit()
+
+        glEnable(GL_TEXTURE_2D)
+        glClearColor(0.0, 0.0, 0.0, 0.0)    # This Will Clear The Background Color To Black
+        glClearDepth(1.0)                                   # Enables Clearing Of The Depth Buffer
+        glDepthFunc(GL_LESS)                                # The Type Of Depth Test To Do
+        glEnable(GL_DEPTH_TEST)                             # Enables Depth Testing
+        glShadeModel(GL_SMOOTH)                             # Enables Smooth Color Shading
+            
+        #glMatrixMode(GL_PROJECTION)
+        #glLoadIdentity()                                    # Reset The Projection Matrix
+                                                            # Calculate The Aspect Ratio Of The Window
+        #gluPerspective(45.0, float(64)/float(64), 0.1, 100.0)
+        glMatrixMode(GL_MODELVIEW)
+init_GL.done = False
+
+class PBufRenderer(object):
+    """Render an OpenGL program to a framebuffer instead of the screen.
+
+    The way to use this class is to enclose all the OpenGL commands you want to render between
+    a call to setup() and a call to render().  So you would render a frame like this:
+
+    .. code-block:: python
+        
+        p = PBufRenderer(shape)
+        p.setup()
+        my_display_code()
+        a = p.render()
+        my_display_code()
+        b = p.render()
+
+    After running this code, 'a' and 'b' will be numpy arrays of shape `shape` + (3,) containing an
+    RBG rendering of your display_code.
+    """
+    def __init__(self, size=(128,128), upside_down=False):
+        """ Offscreen rendering
+        
+        Save an offscreen rendering of size (w,h) to filename.
+        """
+        
+        def round2 (n):
+            """ Get nearest power of two superior to n """
+            f = 1
+            while f<n:
+                f*= 2
+            return f
+
+        if size == None:
+            size = (512,512)
+        w = round2 (size[0])
+        h = round2 (size[1])
+
+        image = Image.new ("RGB", (w, h), (0, 0, 0))
+        bits = image.tostring("raw", "RGBX", 0, -1)
+
+        debug('allocating framebuffer')
+        framebuffer = glGenFramebuffersEXT (1)
+        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer)
+
+        debug('allocating depthbuffer')
+        depthbuffer = glGenRenderbuffersEXT (1)
+        glBindRenderbufferEXT (GL_RENDERBUFFER_EXT,depthbuffer)
+        glRenderbufferStorageEXT (GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, w, h)
+        
+        # Create texture to render to
+        debug('allocating dynamic texture')
+        texture = glGenTextures (1)
+        glBindTexture (GL_TEXTURE_2D, texture)
+        glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
+        glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
+        # Question: why do we need to upload a texture that we are rendering *to* ?
+        glTexImage2D (GL_TEXTURE_2D, 0, GL_RGB, w, h, 0,
+                        GL_RGB, GL_UNSIGNED_BYTE, bits)
+
+        # store variables for later use.
+        self.texture = texture
+        self.framebuffer = framebuffer
+        self.depthbuffer = depthbuffer
+        self.image = image
+        self.bits = bits
+        self.size = size
+        self.texture_size = (w,h)
+        self.upside_down = upside_down
+
+        # set the screen as output
+        glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, 0)
+        glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0)
+
+    def __del__(self):
+        glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, 0)
+        glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0)
+        glDeleteTextures (1,[self.texture])
+        glDeleteFramebuffersEXT (1, [self.framebuffer])
+        glDeleteRenderbuffersExt (1, [self.depthbuffer])
+
+    def setup(self):
+        glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, self.depthbuffer)
+        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,  self.framebuffer)
+        glFramebufferTexture2DEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+                                   GL_TEXTURE_2D,  self.texture, 0);
+        glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, 
+                                     GL_RENDERBUFFER_EXT,  self.depthbuffer);
+                                    
+        status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
+        if status != GL_FRAMEBUFFER_COMPLETE_EXT:
+            raise RuntimeError( "Error in framebuffer activation")
+
+        # Re-orient viewport
+        glViewport (0, 0, self.size[0], self.size[1])
+        glMatrixMode (GL_PROJECTION)
+        glLoadIdentity()
+        gluPerspective (40.,self.size[0]/float(self.size[1]),1.,40.)
+        glMatrixMode (GL_MODELVIEW)
+        glLoadIdentity()
+        gluLookAt (0,0,10, 0,0,0, 0,1,0)
+
+    def render(self):
+        # TODO: Can we get away with glFlush?
+        glFinish() #renders to our framebuffer
+
+        # read back the framebuffer to self.image
+        glBindTexture (GL_TEXTURE_2D, self.texture)
+        w,h = self.texture_size
+        data = glReadPixels (0, 0, w, h, GL_RGB,  GL_UNSIGNED_BYTE)
+        rval = numpy.fromstring(data, dtype='uint8', count=w*h*3).reshape((w,h,3))
+        if self.size != self.texture_size:
+            rval = rval[:self.size[0], :self.size[1],:]
+
+        # return to default state of screen rendering
+        glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, 0)
+        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,  0)
+        if self.upside_down:
+            return rval
+        else:
+            return rval[::-1,:,:]
+
+class OpenGlMovieFromImage(theano.Op):
+    """Helper base class to factor code used by Ops that want to make a movie from an input
+    image, using OpenGL.  The subclass specifies how to actually make the movie.
+    """
+
+    def __init__(self, width, height, upside_down=False):
+        """To set up the renderer, we need to know the frame size of the images.
+        Setting up the renderer for each image is much slower.
+        """
+        init_GL() #global initialization is no-op after first call
+        self.width=width
+        self.height=height
+        self.upside_down=upside_down
+
+        self.renderer = None
+        # Delay construction of renderer until after merge-optimization
+        #PBufRenderer((width, height), upside_down=upside_down)
+
+        #TODO: put texture into output state as reusable resource
+        self.texture = glGenTextures(1)
+
+    def __del__(self):
+        glDeleteTextures (1,[self.texture])
+
+    def __eq__(self, other):
+        return type(self) == type(other) \
+                and self.width == other.width \
+                and self.height == other.height \
+                and self.upside_down == other.upside_down
+
+    def __hash__(self):
+        return hash(type(self)) ^ hash(self.width) ^ hash(self.height) ^ hash(self.upside_down)
+
+    def make_node(self, x, istate):
+        _x = theano.tensor.as_tensor_variable(x)
+        if _x.type.dtype != 'uint8':
+            raise TypeError('must be 2- or 3-tensor of uint8', x)
+        if _x.type.broadcastable != (False, False) \
+                and _x.type.broadcastable != (False, False, False):
+            raise TypeError('must be a 2- or 3-tensor of uint8', x)
+        if not isinstance(istate, theano.Variable):
+            raise TypeError("variable expected", istate)
+        o_type = theano.tensor.TensorType(dtype='uint8', broadcastable=[False, False, False, False])
+        state_type = theano.gof.type.generic
+        return theano.Apply(self, [x, istate], [o_type(), state_type()])
+
+    def perform(self, node, (x, istate), (z_storage, ostate_storage)):
+        if self.renderer is None:
+            self.renderer = PBufRenderer((self.width, self.height), upside_down=self.upside_down)
+
+        ostate = copy.deepcopy(istate)
+        self.renderer.setup() 
+
+        glBindTexture(GL_TEXTURE_2D, self.texture)   # 2d texture (x and y size)
+        load_texture(x)
+
+        z = numpy.zeros(self.z_shape, dtype='uint8')
+        for i in xrange(self.n_frames):
+            self.perform_set_state(istate, ostate, i)
+            self.perform_display(x, ostate, i)
+            di = self.renderer.render()
+            z[i] = di
+
+        # store output images 
+        z_storage[0] = z
+
+        # store next state ostate_storage
+        ostate_storage[0] = ostate
+
+class ImageOnSpinningCube(OpenGlMovieFromImage):
+    def __init__(self, (n_frames, width, height), upside_down=False):
+        super(ImageOnSpinningCube, self).__init__(width, height, upside_down=upside_down)
+        self.n_frames = n_frames
+        self.z_shape = (n_frames, width, height, 3)
+
+    def __eq__(self, other):
+        return super(ImageOnSpinningCube, self).__eq__(other) \
+                and self.n_frames == other.n_frames \
+
+    def __hash__(self):
+        return super(ImageOnSpinningCube, self).__hash__() ^ hash(self.n_frames)
+
+    def new_state(self, speed=10):
+        return dict(
+                rot=numpy.asarray((0.,0.,0.)),
+                drot=numpy.asarray((speed,speed,speed)),
+                )
+
+    def perform_set_state(self, istate, ostate, iter):
+        ostate['rot'] = istate['rot'] + istate['drot'] * iter
+
+    def perform_display(self, x, ostate, i):
+        # retrieve some state variables related to rendering
+        xrot,yrot,zrot = ostate['rot']
+        dxrot,dyrot,dzrot = ostate['drot']
+
+        # load x as a texture
+        glBindTexture(GL_TEXTURE_2D, self.texture)   # 2d texture (x and y size)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
+        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL)
+
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)      # Clear The Screen And The Depth Buffer
+        glLoadIdentity()                                        # Reset The View
+        glTranslatef(0.0,0.0,-5.0)                      # Move Into The Screen
+
+        glRotatef(xrot,1.0,0.0,0.0)                     # Rotate The Cube On It's X Axis
+        glRotatef(yrot,0.0,1.0,0.0)                     # Rotate The Cube On It's Y Axis
+        glRotatef(zrot,0.0,0.0,1.0)                     # Rotate The Cube On It's Z Axis
+
+        glBegin(GL_QUADS)                           # Start Drawing The Cube
+        
+        # Front Face (note that the texture's corners have to match the quad's corners)
+        glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f( 1.0, -1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f( 1.0,  1.0,  1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f(-1.0,  1.0,  1.0)    # Top Left Of The Texture and Quad
+        
+        # Back Face
+        glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0, -1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f(-1.0,  1.0, -1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f( 1.0,  1.0, -1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f( 1.0, -1.0, -1.0)    # Bottom Left Of The Texture and Quad
+        
+        # Top Face
+        glTexCoord2f(0.0, 1.0); glVertex3f(-1.0,  1.0, -1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f(-1.0,  1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f( 1.0,  1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f( 1.0,  1.0, -1.0)    # Top Right Of The Texture and Quad
+        
+        # Bottom Face       
+        glTexCoord2f(1.0, 1.0); glVertex3f(-1.0, -1.0, -1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f( 1.0, -1.0, -1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f( 1.0, -1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        
+        # Right face
+        glTexCoord2f(1.0, 0.0); glVertex3f( 1.0, -1.0, -1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f( 1.0,  1.0, -1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f( 1.0,  1.0,  1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f( 1.0, -1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        
+        # Left Face
+        glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0, -1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f(-1.0,  1.0,  1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f(-1.0,  1.0, -1.0)    # Top Left Of The Texture and Quad
+        
+        glEnd();                                # Done Drawing The Cube
+
+def image_on_spinning_cube(x, shape, upside_down=False):
+    op = ImageOnSpinningCube(shape, upside_down=upside_down)
+    istate = shared(op.new_state())
+    z, ostate = op(x, istate)
+    return z, {istate: ostate}
+
+class BrownianCamera(OpenGlMovieFromImage):
+    def __init__(self, (n_frames, width, height), upside_down=False):
+        super(BrownianCamera, self).__init__(width, height, upside_down=upside_down)
+        self.n_frames = n_frames
+        self.z_shape = (n_frames, width, height, 3)
+
+    def __eq__(self, other):
+        return super(self.__class__, self).__eq__(other) \
+                and self.n_frames == other.n_frames \
+
+    def __hash__(self):
+        return super(self.__class__, self).__hash__() ^ hash(self.n_frames)
+
+    def new_state(self, pos_jitter=(.01,.01,.03), rot_jitter=(4.,4.,4.), seed=23424):
+        return dict(
+                pos_jitter=numpy.asarray(pos_jitter),
+                rot_jitter=numpy.asarray(rot_jitter),
+                pos0=numpy.asarray((0.,0.,-4.0)),
+                rot0=numpy.asarray((0.,0.,0.)),
+                alpha=0.1,
+                # dynamic things
+                pos=numpy.asarray((0.,0.,-4.0)),
+                dpos=numpy.asarray((0.,0.,0.)),
+                ddpos=numpy.asarray((0.,0.,0.)),
+                rot=numpy.asarray((0.,0.,0.)),
+                drot=numpy.asarray((0.,0.,0.)),
+                ddrot=numpy.asarray((0.,0.,0.)),
+                rng = numpy.random.RandomState(seed),
+                )
+
+    def perform_set_state(self, istate, ostate, iter):
+        alpha = ostate['alpha']
+        if iter == 0:
+            ostate['pos'] = ostate['pos0'].copy()
+            ostate['dpos'] *= 0
+            ostate['rot'] = ostate['rot0'].copy()
+            ostate['drot'] *= 0
+        ostate['ddpos'] = ostate['rng'].uniform(low=-1,high=1,size=3) * ostate['pos_jitter']
+        ostate['ddrot'] = ostate['rng'].uniform(low=-1,high=1,size=3) * ostate['rot_jitter']
+        ostate['dpos'] += ostate['ddpos']
+        ostate['drot'] += ostate['ddrot']
+        ostate['pos'] = (1-alpha)*(ostate['pos'] + ostate['dpos']) + alpha * ostate['pos0']
+        ostate['rot'] = (1-alpha)*(ostate['rot'] + ostate['drot']) + alpha * ostate['rot0']
+
+    def perform_display(self, x, ostate, i):
+        # retrieve some state variables related to rendering
+        xrot,yrot,zrot = ostate['rot']
+        xpos,ypos,zpos = ostate['pos']
+
+        # load x as a texture
+        glBindTexture(GL_TEXTURE_2D, self.texture)   # 2d texture (x and y size)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
+        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL)
+
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)      # Clear The Screen And The Depth Buffer
+        glLoadIdentity()                                        # Reset The View
+        glTranslatef(xpos,ypos,zpos)                      # Move Into The Screen
+
+        glRotatef(xrot,1.0,0.0,0.0)                     # Rotate The Cube On It's X Axis
+        glRotatef(yrot,0.0,1.0,0.0)                     # Rotate The Cube On It's Y Axis
+        glRotatef(zrot,0.0,0.0,1.0)                     # Rotate The Cube On It's Z Axis
+
+        glBegin(GL_QUADS)                           # Start Drawing The Cube
+        
+        # Front Face (note that the texture's corners have to match the quad's corners)
+        glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f( 1.0, -1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f( 1.0,  1.0,  1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f(-1.0,  1.0,  1.0)    # Top Left Of The Texture and Quad
+        
+        glEnd();                                # Done Drawing The Cube
+
+_brownian_camera_ops = {}
+def brownian_camera(x, shape, upside_down=False, seed=8234, speed=1.0):
+    if (shape, upside_down) not in _brownian_camera_ops:
+        _brownian_camera_ops[(shape, upside_down)] = BrownianCamera(shape, upside_down=upside_down)
+    op = _brownian_camera_ops[(shape, upside_down)]
+    istate = shared(op.new_state(seed=seed))
+    istate.value['pos_jitter'] *= speed
+    istate.value['rot_jitter'] *= speed
+    z, ostate = op(x, istate)
+    return z, [(istate, ostate)]
+
+
+def _dump_to_file(fn, filename='out.pkl', nexamples=1000, n_frames=10, **kwargs):
+    logging.basicConfig(level=logging.INFO, stream=sys.stderr)
+    import cPickle, time
+
+    from MNIST import mnist
+    i = theano.tensor.iscalar()
+    z, z_updates = fn(mnist(i%50000, 'train', rasterized=False, dtype='uint8')[0], (n_frames, 28,28), **kwargs)
+    f = function([i], z[:,:,:,0], updates=z_updates)
+
+    t0 = time.time()
+    rval = []
+    for j in xrange(nexamples):
+        if 0 == j  % 100: print >> sys.stderr, j
+        rval.append(f(j))
+    dt = time.time() - t0
+    info('Generating ', nexamples, 'examples took', dt, 'seconds.')
+    info('Generation rate:', nexamples/dt, 'examples per second.')
+    info('Generated ', nexamples*n_frames, 'frames')
+    info('Generation rate:', nexamples*n_frames/dt, 'frames per second.')
+
+    cPickle.dump(rval, file(filename, 'w'), protocol=cPickle.HIGHEST_PROTOCOL)
+def spinning_cube_dump(filename='spinning_cube.pkl', *args, **kwargs):
+    return _dump_to_file(fn=image_on_spinning_cube, filename=filename, *args, **kwargs)
+def brownian_camera_dump(filename='brownian_camera.pkl', *args, **kwargs):
+    return _dump_to_file(fn=brownian_camera, filename=filename, *args, **kwargs)
+def brownian_camera_dumpN(filename='brownian_cameraN.pkl', nexamples=10, n_frames=5,
+        n_movies=10, img_shape=(28,28), **kwargs):
+    logging.basicConfig(level=logging.INFO, stream=sys.stderr)
+    import cPickle, time
+    from MNIST import mnist
+
+    s_idx = theano.tensor.iscalar()
+    inputs_updates = [brownian_camera(
+            x=mnist(s_idx*n_movies+i, 'train', rasterized=False, dtype='uint8')[0],
+            shape=(n_frames,)+img_shape,
+            seed=234234+i, **kwargs)
+        for i in xrange(n_movies)]
+    s_input = theano.tensor.stack(*(input for (input,update) in inputs_updates))\
+            .reshape((n_movies*n_frames,)+img_shape+(3,))
+    s_updates = []
+    for i,u in inputs_updates:
+        s_updates.extend(u)
+    print s_updates
+    f = function([s_idx], s_input, updates=s_updates)
+
+    t0 = time.time()
+    rval = []
+    for j in xrange(nexamples):
+        if 0 == j  % 1000: print >> sys.stderr, j
+        rval.append(f(j))
+    dt = time.time() - t0
+    info('Generating ', nexamples, 'examples took', dt, 'seconds.')
+    info('Generation rate:', nexamples/dt, 'examples per second.')
+    info('Generated ', nexamples*n_movies*n_frames, 'frames')
+    info('Generation rate:', nexamples*n_movies*n_frames/dt, 'frames per second.')
+
+    cPickle.dump(rval, file(filename, 'w'))
+
+
+def glviewer_from_file(filename='out.pkl'):
+    logging.basicConfig(level=logging.DEBUG, stream=sys.stderr)
+    import cPickle
+    rval = cPickle.load(file(filename))
+    from glviewer import GlViewer
+    GlViewer(rval.__getitem__).main()
+
+
diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/glviewer.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/glviewer.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,367 @@
+"""This file provides a very crude image-viewing and movie-viewing mini-application.
+
+It is provided to assist in the development of datasets whose elements are images or movies.
+For an example of how to do this, see the `glviewer` function in MNIST.py .
+
+Currently, the key controls that navigate the dataset are:
+
+    j - next dataset element
+    k - previous dataset element
+    0 - show image 0
+
+    J - next frame in current movie
+    K - previous frame in current movie
+    ) - show frame 0 of current movie
+
+    q - quit.
+"""
+# Modified to be an image viewer by James Bergstra Sept 2009
+#
+# Ported to PyOpenGL 2.0 by Tarn Weisner Burton 10May2001
+#
+# This code was created by Richard Campbell '99 (ported to Python/PyOpenGL by John Ferguson 2000)
+#
+# The port was based on the lesson5 tutorial module by Tony Colston (tonetheman@hotmail.com).  
+#
+# If you've found this code useful, please let me know (email John Ferguson at hakuin@voicenet.com).
+#
+# See original source and C based tutorial at http:#nehe.gamedev.net
+#
+
+
+import traceback
+import time
+import string
+from OpenGL.GL import *
+from OpenGL.GLUT import *
+from OpenGL.GLU import *
+import sys
+from Image import *
+import numpy
+
+import logging
+_logger = logging.getLogger('glviewer')
+_logger.setLevel(logging.INFO)
+def debug(*msg): _logger.debug(' '.join(str(m) for m in msg))
+def info(*msg): _logger.info(' '.join(str(m) for m in msg))
+def warn(*msg): _logger.warn(' '.join(str(m) for m in msg))
+def warning(*msg): _logger.warning(' '.join(str(m) for m in msg))
+def error(*msg): _logger.error(' '.join(str(m) for m in msg))
+
+def load_texture(x):
+    debug('loading texture with shape', x.shape)
+    if x.ndim == 2:
+        if x.dtype == 'uint8':
+            rows, cols = x.shape
+            buf = numpy.zeros((rows, cols, 4), dtype=x.dtype)
+            buf += x.reshape( (rows, cols, 1))
+            glPixelStorei(GL_UNPACK_ALIGNMENT,1)
+            return glTexImage2D(GL_TEXTURE_2D, 0, 3, cols, rows, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+                    buf[::-1].flatten())
+        else:
+            raise NotImplementedError()
+    elif x.ndim == 3:
+        rows, cols, channels = x.shape
+        if x.dtype == 'uint8':
+            if channels == 4:
+                return glTexImage2D(GL_TEXTURE_2D, 0, 3, cols, rows, 0, GL_RGBA, GL_UNSIGNED_BYTE, x[::-1].flatten())
+            else:
+                buf = numpy.zeros((rows, cols, 4), dtype=x.dtype)
+                if channels == 1:
+                    buf += x.reshape( (rows, cols, 1))
+                if channels == 3:
+                    buf[:,:,:3] = x
+                return glTexImage2D(GL_TEXTURE_2D, 0, 3, cols, rows, 0, GL_RGBA, GL_UNSIGNED_BYTE, buf[::-1].flatten())
+        else:
+            raise NotImplementedError()
+    else:
+        raise NotImplementedError()
+
+    # if you get here, it means a case was missed
+    assert 0
+
+
+class GlViewer(object):
+    # Number of the glut window.
+    window = 0
+
+    view_angle = 28.0  # this makes the edge of the cube match up with the viewport
+
+    def __init__(self, texture_fn):
+
+        # Rotations for cube. 
+        self.xrot = self.yrot = self.zrot = 0.0
+
+        self.texture = 0
+
+        self.texture_fn = texture_fn
+
+        self.pos = -1
+        self.pos_frame = -1
+        self.pos_is_movie = False
+        self.texture_array = None
+
+        self.win_shape = (256, 256)
+        self.rot = numpy.zeros(3)
+        self.drot = numpy.ones(3) * .0
+
+    def init_LoadTextures(self):
+        # Create Texture    
+        glBindTexture(GL_TEXTURE_2D, glGenTextures(1))   # 2d texture (x and y size)
+        self.refresh_texture(0, 0)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
+        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL)
+        
+        
+    # A general OpenGL initialization function.  Sets all of the initial parameters. 
+    def init_GL(self):
+        glEnable(GL_TEXTURE_2D)
+        glClearColor(0.0, 0.0, 0.0, 0.0)    # This Will Clear The Background Color To Black
+        glClearDepth(1.0)                   # Enables Clearing Of The Depth Buffer
+        glDepthFunc(GL_LESS)                # The Type Of Depth Test To Do
+        glEnable(GL_DEPTH_TEST)             # Enables Depth Testing
+        glShadeModel(GL_SMOOTH)             # Enables Smooth Color Shading
+            
+        glMatrixMode(GL_PROJECTION)
+        glLoadIdentity()                    # Reset The Projection Matrix
+                                            # Calculate The Aspect Ratio Of The Window
+        Width, Height = self.win_shape
+        gluPerspective(self.view_angle, float(Width)/float(Height), 0.1, 100.0)
+
+        glMatrixMode(GL_MODELVIEW)
+
+    def main(self):
+        #
+        # texture gen: an iterator over images
+        #
+        # Call this function like this:
+        # python -c 'import MNIST, glviewer; glviewer.main(x for (x,y) in MNIST.MNIST().train())'
+        #
+
+        #TODO: this advances the iterator un-necessarily... we just want a frame to look at the
+        #      dimensions
+
+        global window
+        glutInit(sys.argv)
+
+        # Select type of Display mode:   
+        #  Double buffer 
+        #  RGBA color
+        # Alpha components supported 
+        # Depth buffer
+        info('initializing OpenGl subsystem')
+        ##glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
+
+        win_width, win_height = self.win_shape
+        
+        # get a 640 x 480 window 
+        ##glutInitWindowSize(win_width, win_height)
+        
+        # the window starts at the upper left corner of the screen 
+        glutInitWindowPosition(0, 0)
+        
+        # Okay, like the C version we retain the window id to use when closing, but for those of you new
+        # to Python (like myself), remember this assignment would make the variable local and not global
+        # if it weren't for the global declaration at the start of main.
+        window = glutCreateWindow("GlViewer")
+
+        # Register the drawing function with glut, BUT in Python land, at least using PyOpenGL, we need to
+        # set the function pointer and invoke a function to actually register the callback, otherwise it
+        # would be very much like the C version of the code.    
+        glutDisplayFunc(self.draw_scene)
+        
+        # Uncomment this line to get full screen.
+        # glutFullScreen()
+
+        # When we are doing nothing, redraw the scene.
+        glutIdleFunc(self.on_idle)
+        
+        # Register the function called when our window is resized.
+        glutReshapeFunc(self.ReSizeGLScene)
+        
+        # Register the function called when the keyboard is pressed.  
+        glutKeyboardFunc(self.keyPressed)
+
+        # create the texture we will use for showing images
+        self.init_LoadTextures()
+
+        # Initialize our window. 
+        self.init_GL()
+
+        # Start Event Processing Engine 
+        glutMainLoop()
+
+    # The function called when our window is resized (which shouldn't happen if you enable fullscreen, below)
+    def ReSizeGLScene(self, Width, Height):
+        if Height == 0:                       # Prevent A Divide By Zero If The Window Is Too Small 
+            Height = 1
+
+        glViewport(0, 0, Width, Height)       # Reset The Current Viewport And Perspective Transformation
+        glMatrixMode(GL_PROJECTION)
+        glLoadIdentity()
+        gluPerspective(self.view_angle, float(Width)/float(Height), 0.1, 100.0)
+        glMatrixMode(GL_MODELVIEW)
+
+        self.win_shape = (Width, Height)
+
+
+    def refresh_texture(self, new_pos, new_frame):
+        debug('refresh_texture', new_pos, new_frame, 'current', self.pos, self.pos_frame)
+        if new_pos != self.pos:
+            texture_array = None
+            try:
+                texture_array = self.texture_fn(new_pos)
+            except Exception, e:
+                traceback.print_exc()
+
+            if texture_array is None:
+                return
+            # calling the texture_fn can mess up the OpenGL state
+            # here we set it up again
+            self.init_GL()
+
+            self.pos_is_movie=False
+            if texture_array.ndim == 4:
+                self.pos_is_movie = True
+            if texture_array.ndim == 3 and texture_array.shape[2] > 4:
+                self.pos_is_movie = True
+
+            self.pos = new_pos
+            self.texture_array = texture_array
+            pos_changed = True
+            if self.pos_is_movie:
+                info('example', new_pos, 'is movie of', texture_array.shape[0], 'frames')
+            else:
+                info('example', new_pos, 'is still frame')
+        else:
+            pos_changed = False
+            texture_array = self.texture_array
+
+        if new_frame == self.pos_frame and not pos_changed:
+            # nothing to do
+            return
+
+        if self.pos_is_movie:
+            n_frames = texture_array.shape[0]
+            if n_frames > new_frame:
+                self.pos_frame = new_frame
+                load_texture(texture_array[new_frame])
+            else:
+                # current frame goes beyond end of movie
+                pass 
+        else: 
+            # this example is a static frame
+            load_texture(texture_array)
+
+    # The main drawing function. 
+    def on_idle(self):
+        # update state stuff pre-draw
+        self.draw_scene()
+
+        # update state stuff post draw
+        self.rot += self.drot
+
+    def draw_scene(self):
+
+        xrot, yrot, zrot = self.rot
+
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)      # Clear The Screen And The Depth Buffer
+        glLoadIdentity()                                        # Reset The View
+        glTranslatef(0.0,0.0,-5.0)                      # Move Into The Screen
+
+        glRotatef(xrot,1.0,0.0,0.0)                     # Rotate The Cube On It's X Axis
+        glRotatef(yrot,0.0,1.0,0.0)                     # Rotate The Cube On It's Y Axis
+        glRotatef(zrot,0.0,0.0,1.0)                     # Rotate The Cube On It's Z Axis
+    
+        # Note there does not seem to be support for this call.
+        #glBindTexture(GL_TEXTURE_2D,texture)   # Rotate The Pyramid On It's Y Axis
+
+        glBegin(GL_QUADS)                           # Start Drawing The Cube
+        
+        # Front Face (note that the texture's corners have to match the quad's corners)
+        glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f( 1.0, -1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f( 1.0,  1.0,  1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f(-1.0,  1.0,  1.0)    # Top Left Of The Texture and Quad
+        
+        # Back Face
+        glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0, -1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f(-1.0,  1.0, -1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f( 1.0,  1.0, -1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f( 1.0, -1.0, -1.0)    # Bottom Left Of The Texture and Quad
+        
+        # Top Face
+        glTexCoord2f(0.0, 1.0); glVertex3f(-1.0,  1.0, -1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f(-1.0,  1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f( 1.0,  1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f( 1.0,  1.0, -1.0)    # Top Right Of The Texture and Quad
+        
+        # Bottom Face       
+        glTexCoord2f(1.0, 1.0); glVertex3f(-1.0, -1.0, -1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f( 1.0, -1.0, -1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f( 1.0, -1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        
+        # Right face
+        glTexCoord2f(1.0, 0.0); glVertex3f( 1.0, -1.0, -1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f( 1.0,  1.0, -1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f( 1.0,  1.0,  1.0)    # Top Left Of The Texture and Quad
+        glTexCoord2f(0.0, 0.0); glVertex3f( 1.0, -1.0,  1.0)    # Bottom Left Of The Texture and Quad
+        
+        # Left Face
+        glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0, -1.0)    # Bottom Left Of The Texture and Quad
+        glTexCoord2f(1.0, 0.0); glVertex3f(-1.0, -1.0,  1.0)    # Bottom Right Of The Texture and Quad
+        glTexCoord2f(1.0, 1.0); glVertex3f(-1.0,  1.0,  1.0)    # Top Right Of The Texture and Quad
+        glTexCoord2f(0.0, 1.0); glVertex3f(-1.0,  1.0, -1.0)    # Top Left Of The Texture and Quad
+        
+        glEnd();                                # Done Drawing The Cube
+
+        #  since this is double buffered, swap the buffers to display what just got drawn. 
+        glutSwapBuffers()
+
+    # The function called whenever a key is pressed. Note the use of Python tuples to pass in: (key, x, y)  
+    def keyPressed(self, *args):
+        ESCAPE = '\033'
+
+        # EXAMPLE CONTROLS
+
+        if args[0] == 'j': # down
+            self.refresh_texture(self.pos + 1, 0)
+            info( 'Current image: ', self.pos)
+        elif args[0] == 'k': # up
+            self.refresh_texture(self.pos - 1, 0)
+            info( 'Current image: ', self.pos)
+        elif args[0] == '0': # reset to position 0
+            self.refresh_texture(0, 0)
+            info( 'Current image: ', self.pos)
+
+        # FRAME CONTROLS
+
+        elif args[0] == ')': # ')' is shift-0,  reset to frame 0
+            self.refresh_texture(self.pos, 0)
+            info( 'Current image: ', self.pos)
+        elif args[0] == 'J': # advance frame
+            self.refresh_texture(self.pos, self.pos_frame + 1)
+            info( 'Next frame')
+        elif args[0] == 'K': # advance frame
+            if self.pos_frame:
+                self.refresh_texture(self.pos, self.pos_frame - 1)
+                info( 'Previous frame')
+            else:
+                warn('Not backing up past frame 0')
+
+        elif args[0] == ESCAPE or args[0]=='q':
+            sys.exit()
+
+
+if __name__ == '__main__':
+
+    sample_data = numpy.asarray(numpy.random.randint(low=0, high=256, size=(5, 64,64)),
+    dtype='uint8')
+    GlViewer(sample_data.__getitem__).main()
+
diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/memo.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/memo.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,22 @@
+"""Provide a decorator that caches expensive functions
+"""
+import logging
+_logger = logging.getLogger(__file__)
+info = _logger.info
+def infop(*args):
+    info(' '.join(str(a) for a in args))
+
+def memo(f):
+    #TODO: support kwargs to rval.  This requires looking up the names of f's parameters to 
+    #      construct a proper key.
+
+    #TODO: use weak references instead of a normal dict so that the cache doesn't prevent
+    #      garbage collection
+    cache = {}
+    def rval(*args):
+        if args not in cache:
+            cache[args] = f(*args)
+        return cache[args]
+    rval.__name__ = 'memo@%s'%f.__name__
+    return rval
+
diff -r 43e726898cf9 -r 67b92a42f86b pylearn/dataset_ops/protocol.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pylearn/dataset_ops/protocol.py	Fri Oct 16 12:04:05 2009 -0400
@@ -0,0 +1,83 @@
+"""Convenience base classes to help with writing Dataset ops
+
+"""
+
+__docformat__  = "restructuredtext_en"
+import theano
+
+class Dataset(theano.Op):
+    """ 
+    The basic dataset interface is an expression that maps an integer to a dataset element.
+
+    There is also a minibatch option, in which the expression maps an array of integers to a
+    list or array of dataset elements.
+    """
+    def __init__(self, single_type, batch_type):
+        self.single_type = single_type
+        self.batch_type = batch_type
+
+    def make_node(self, idx):
+        _idx = theano.tensor.as_tensor_variable(idx)
+        if not _idx.dtype.startswith('int'):
+            raise TypeError()
+        if _idx.ndim == 0: # one example at a time
+            otype = self.single_type
+        elif _idx.ndim == 1: #many examples at a time
+            otype = self.batch_type
+        else:
+            raise TypeError(idx)
+        return theano.Apply(self, [_idx], [otype()])
+
+    def __eq__(self, other):
+        return type(self) == type(other) \
+                and self.single_type == other.single_type \
+                and self.batch_type == other.batch_type
+
+    def __hash__(self):
+        return hash(type(self)) ^ hash(self.single_type) ^ hash(self.batch_type)
+
+    def __str__(self):
+        return "%s{%s,%s}" % (self.__class__.__name__, self.single_type, self.batch_type)
+
+    def grad(self, inputs, g_outputs):
+        return [None for i in inputs]
+
+
+class TensorDataset(Dataset):
+    """A convenient base class for Datasets whose elements all have the same TensorType.
+    """
+    def __init__(self, dtype, single_broadcastable, single_shape=None, batch_size=None):
+        single_broadcastable = tuple(single_broadcastable)
+        single_type = theano.tensor.Tensor(
+                broadcastable=single_broadcastable, 
+                dtype=dtype,
+                shape=single_shape)
+        batch_type = theano.tensor.Tensor(
+                broadcastable=(False,)+single_type.broadcastable,
+                dtype=dtype,
+                shape=(batch_size,)+single_type.shape)
+        super(TensorDataset, self).__init__(single_type, batch_type)
+
+class TensorFnDataset(TensorDataset):
+    def __init__(self, dtype, bcast, fn, single_shape=None, batch_size=None):
+        super(TensorFnDataset, self).__init__(dtype, bcast, single_shape, batch_size)
+        self.fn = fn
+
+    def __eq__(self, other):
+        return super(TensorFnDataset, self).__eq__(other) and self.fn == other.fn
+
+    def __hash__(self):
+        return super(TensorFnDataset, self).__hash__() ^ hash(self.fn)
+
+    def __str__(self):
+        try:
+            return "%s{%s}" % (self.__class__.__name__, self.fn.__name__)
+        except:
+            return "%s{%s}" % (self.__class__.__name__, self.fn)
+
+    def perform(self, node, (idx,), (z,)):
+        x = self.fn()
+        if idx.ndim == 0:
+            z[0] = x[int(idx)]
+        else:
+            z[0] = x[idx]