def test_cmm(n = 10000, cutoff = 50, a = 100, nbin = 10, ntrials = 100):
"Tests multipole approximations to electrostatic potential"
bindims = (nbin,nbin,nbin)
bbox = (-a,a,-a,a,-a,a)
print " n = %d, a = %d, cut = %d, nbin = %d" % (n,a,cutoff,nbin)
tfull = []
tbin = []
tvbin = []
rms = 0
for i in range(ntrials):
points = RandomQs(n,bbox) # Create a random set of charges
xyz = RandomPosition(bbox) # Select a random position
t0 = time()
vfull = full_potential(xyz,points)
t1 = time()
tfull.append(t1-t0)
cmm = CMM(bindims,points)
t2 = time()
tbin.append(t2-t1)
vbin = cmm.pot(xyz)
t3 = time()
tvbin.append(t3-t2)
rms += pow(vfull-vbin,2)
print "Trial %d: %10.4f %10.4f" % (i,vfull,vbin)
print "Average times: %10.4f %10.4f %10.4f" %\
(avg(tfull),avg(tbin),avg(tvbin))
print "RMS error: ",sqrt(rms/ntrials)
return
def full_potential(self,xyz): return full_potential(xyz,self._points)
def mp_potential(self,xyz):