Theano test script, but computing exp on the GPU using gpu_from_host to wrap T.exp()

gpu_from_host.py

from theano import function, config, shared, sandbox
import theano.tensor as T
import numpy
import time

from datetime import datetime

from optparse import OptionParser
import os

parser = OptionParser()
parser.add_option("-d", "--dir", dest="dir", help="test output directory")

(options, args) = parser.parse_args()

vlen = 10 * 448 * 768  # 10 x #cores x # threads per core
iters = 1000

os.chdir(options.dir)
today = datetime.today()
day = str(today.date())
hour = str(today.time())
output_filename = "from_host_test." + day + "." + hour
output_file = open(output_filename,'w')

print >> output_file, "Run on " + str(datetime.now())

rng = numpy.random.RandomState(22)
x = shared(numpy.asarray(rng.rand(vlen), config.floatX))
f = function([], sandbox.cuda.basic_ops.gpu_from_host(T.exp(x)))
print f.maker.fgraph.toposort()
t0 = time.time()
for i in xrange(iters):
    r = f()
t1 = time.time()
print >> output_file, 'Looping %d times took' % iters, t1 - t0, 'seconds'
print >> output_file, 'Result is', r
print >> output_file, 'Numpy result is', numpy.asarray(r)
if numpy.any([isinstance(x.op, T.Elemwise) for x in 
f.maker.fgraph.toposort()]):
    print >> output_file, 'Used the cpu'
else:
    print >> output_file, 'Used the gpu'

output_file.close()