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#
# C:\home\eric\wrk\scipy\weave\examples>python ramp2.py
# python (seconds): 2.94499993324
# arr[500]: 0.0500050005001
#
# compiled numeric (seconds, speed up): 3.47500002384 42.3740994682
# arr[500]: 0.0500050005001
import time
from weave import ext_tools
from Numeric import *
def Ramp(result, size, start, end):
step = (end-start)/(size-1)
for i in xrange(size):
result[i] = start + step*i
def build_ramp_ext():
mod = ext_tools.ext_module('ramp_ext')
# type declarations
result = array([0],Float64)
start,end = 0.,0.
code = """
const int size = Nresult[0];
const double step = (end-start)/(size-1);
double val = start;
for (int i = 0; i < size; i++)
{
result[i] = val;
val += step;
}
"""
func = ext_tools.ext_function('Ramp',code,['result','start','end'])
mod.add_function(func)
mod.compile(compiler='gcc')
def main():
arr = [0]*10000
t1 = time.time()
for i in xrange(200):
Ramp(arr, 10000, 0.0, 1.0)
t2 = time.time()
py_time = t2 - t1
print 'python (seconds):', py_time
print 'arr[500]:', arr[500]
print
try:
import ramp_ext
except:
build_ramp_ext()
import ramp_ext
arr = array([0]*10000,Float64)
for i in xrange(10000):
ramp_ext.Ramp(arr, 0.0, 1.0)
t2 = time.time()
c_time = (t2 - t1)
print 'compiled numeric (seconds, speed up):', c_time, (py_time*10000/200.)/ c_time
print 'arr[500]:', arr[500]
if __name__ == '__main__':
main()
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