def bench_random(self,level=5):
print
print ' Shifting periodic functions'
print '=============================='
print ' size | optimized | naive'
print '------------------------------'
for size,repeat in [(100,1500),(1000,300),
(256,1500),
(512,1000),
(1024,500),
(2048,200),
(2048*2,100),
(2048*4,50),
]:
print '%6s' % size,
sys.stdout.flush()
x = arange (size)*2*pi/size
a = 1
if size<2000:
f = sin(x)*cos(4*x)+exp(sin(3*x))
sf = sin(x+a)*cos(4*(x+a))+exp(sin(3*(x+a)))
else:
f = sin(x)*cos(4*x)
sf = sin(x+a)*cos(4*(x+a))
assert_array_almost_equal(direct_shift(f,1),sf)
assert_array_almost_equal(shift(f,1),sf)
print '| %9.2f' % self.measure('shift(f,a)',repeat),
sys.stdout.flush()
print '| %9.2f' % self.measure('direct_shift(f,a)',repeat),
sys.stdout.flush()
print ' (secs for %s calls)' % (repeat)
def check_definition(self):
for n in [18,17,64,127,32,2048,256]:
x = arange(n)*2*pi/n
for a in [0.1,3]:
assert_array_almost_equal(shift(sin(x),a),direct_shift(sin(x),a))
assert_array_almost_equal(shift(sin(x),a),sin(x+a))
assert_array_almost_equal(shift(cos(x),a),cos(x+a))
assert_array_almost_equal(shift(cos(2*x)+sin(x),a),
cos(2*(x+a))+sin(x+a))
assert_array_almost_equal(shift(exp(sin(x)),a),exp(sin(x+a)))
assert_array_almost_equal(shift(sin(x),2*pi),sin(x))
assert_array_almost_equal(shift(sin(x),pi),-sin(x))
assert_array_almost_equal(shift(sin(x),pi/2),cos(x))