[Yt-svn] yt-commit r749 - trunk/yt/lagos

[mturk at wrangler.dreamhost.com]

Author: mturk
Date: Wed Sep  3 09:40:14 2008
New Revision: 749
URL: http://yt.spacepope.org/changeset/749

Log:

This is the slowest ray tracer in the world.

Rather than keep holding off on implementing the algorithm I came up with a
while ago, which is necessarily getting push back further and further as I
try to finish up other projects instead of starting new ones, I've gone ahead
and implemented the simplest, stupidest one, based on existing code in YT.
More to come on this, including (hopefully) some example functions.  This is
just a first draft right now, and will also eventually return some type of
FixedResolutionBuffer.



Added:
   trunk/yt/lagos/RayTracer.py

Added: trunk/yt/lagos/RayTracer.py
==============================================================================
--- (empty file)
+++ trunk/yt/lagos/RayTracer.py	Wed Sep  3 09:40:14 2008
@@ -0,0 +1,73 @@
+"""
+The slowest ray-tracer known to man.
+
+Author: Matthew Turk <matthewturk at gmail.com>
+Affiliation: KIPAC/SLAC/Stanford
+Homepage: http://yt.enzotools.org/
+License:
+  Copyright (C) 2008 Matthew Turk.  All Rights Reserved.
+
+  This file is part of yt.
+
+  yt 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, see <http://www.gnu.org/licenses/>.
+"""
+
+from yt.lagos import *
+
+class SlowRayTracer(object):
+    def __init__(self, pf, axis, bounds, res, func, reverse = False):
+        self.pf = pf
+        self.axis = axis
+        self.x_bounds, self.y_bounds = bounds
+        self.res = res
+        self.func = func
+        self.reverse = reverse
+        self.buff = na.zeros(res, dtype='float64')
+        self.fill_buff()
+
+    def _trace_single_ray(self, x, y):
+        ray = self.pf.h.ray(self.axis, (x, y))
+        order = ray[axis_names[self.axis]].argsort()
+        if self.reverse: order = order[::-1]
+        return self.func(ray, order)
+
+    def fill_buff(self):
+        #pb = get_pbar("Ray tracing ", na.prod(self.res))
+        xs = na.linspace(self.x_bounds[0], self.x_bounds[1], self.res[0])
+        ys = na.linspace(self.y_bounds[0], self.y_bounds[1], self.res[1])
+        #counter = 0
+        for i, x in enumerate(xs.ravel()):
+            #counter += 1
+            print i
+            for j, y in enumerate(ys.ravel()):
+                #pb.update(counter)
+                self.buff[i,j] = self._trace_single_ray(x,y)
+        #pb.finish()
+
+    def __getitem__(self, item):
+        return self.buff[item]
+
+if __name__ == "__main__":
+    def raw_proj(ray, order):
+        return na.sum((ray["Density"]*ray["dx"])[order])
+        #return na.sum((ray["Density"]*ray["dx"])[order])
+    import yt.logger
+    yt.logger.disable_stream_logging()
+    pf = EnzoStaticOutput("/Users/matthewturk/Research/data/galaxy1200.dir/galaxy1200")
+    srt = SlowRayTracer(pf, 0, ((0.0125,1.0-0.0125),(0.0125,1.0-0.0125)),
+                        (256, 256), raw_proj, reverse=False)
+    import pylab
+    pylab.imshow(na.log10(srt.buff), interpolation='nearest', origin='lower')
+    pylab.savefig("srt_raw_x.png")
+    pylab.clf()