From 4b1bea8ccd0f6588c76ec202cada933d5e5047ac Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Fri, 16 Aug 2013 22:22:03 -0500
Subject: [PATCH] Improved pure-py version of Mandelbrot demo
---
examples/demo_mandelbrot.py | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/examples/demo_mandelbrot.py b/examples/demo_mandelbrot.py
index c6a4f50d..e63fec56 100644
--- a/examples/demo_mandelbrot.py
+++ b/examples/demo_mandelbrot.py
@@ -1,6 +1,9 @@
# I found this example for PyCuda here:
# http://wiki.tiker.net/PyCuda/Examples/Mandelbrot
#
+# An improved sequential/pure Python code was contributed
+# by CRVSADER//KY <crusaderky@gmail.com>.
+#
# I adapted it for PyOpenCL. Hopefully it is useful to someone.
# July 2010, HolgerRapp@gmx.net
#
@@ -25,8 +28,8 @@ import pyopencl as cl
# Speed notes are listed in the same place
# set width and height of window, more pixels take longer to calculate
-w = 512
-h = 512
+w = 2048
+h = 2048
def calc_fractal_opencl(q, maxiter):
@@ -70,19 +73,17 @@ def calc_fractal_opencl(q, maxiter):
def calc_fractal_serial(q, maxiter):
- # calculate z using numpy
- # this routine unrolls calc_fractal_numpy as an intermediate
- # step to the creation of calc_fractal_opencl
- # it runs slower than calc_fractal_numpy
- z = np.zeros(q.shape, np.complex64)
+ # calculate z using pure python on a numpy array
+ # note that, unlike the other two implementations,
+ # the number of iterations per point is NOT constant
+ z = np.zeros(q.shape, complex)
output = np.resize(np.array(0,), q.shape)
for i in range(len(q)):
- for it in range(maxiter):
+ for iter in range(maxiter):
z[i] = z[i]*z[i] + q[i]
if abs(z[i]) > 2.0:
- q[i] = 0+0j
- z[i] = 0+0j
- output[i] = it
+ output[i] = iter
+ break
return output
--
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