def solve_update(model,expander,k=10,target_block=None,**kwargs):
'''
Solve using chain updates.
'''
H_serial=op2collection(op=model.hgen.get_opH())
#ion()
#H_serial.show_advanced()
#pdb.set_trace()
t0=time.time()
if isinstance(expander.evolutor,NullEvolutor):
H=get_H(H=H_serial,hgen=expander)
Emin,Evec=eigsh(H,k=k,which='SA',maxiter=5000,v0=random.random(H.shape[0]))
else:
H2,bm2=get_H_bm(H=H_serial,hgen=expander,bstr=model.qnumber)
if target_block is not None:
if hasattr(target_block,'__call__'):
target_block=target_block(model.nsite)
H2=bm2.lextract_block(H2,target_block)
Emin,Evec=eigsh(H2,k=k,which='SA',v0=random.random(H2.shape[0]))
t1=time.time()
print 'The Ground State Energy for %s: %s, Elapse %s.'%(model,array(sorted(Emin)),t1-t0)
return Emin,Evec
def solve1_update(J,nsite,override=True,C2parity=None,h=0.):
'''Get and store the eigen vectors and eigen values for ground state.'''
model=IsingModel(J=J,h=h,nsite=nsite)
spaceconfig=SpinSpaceConfig([2,1])
H_serial=model.H_serial
expander=RGHGen(spaceconfig=spaceconfig,H=H_serial,evolutor_type='null')
t0=time.time()
H=get_H(expander)
Emin,EV=eigsh(H,k=2,which='SA')
t1=time.time()
print 'The Ground State Energy for %s: %s, Elapse %s.'%(model,Emin,t1-t0)
print 'FIN - CORE:%s'%RANK
for i in xrange(2):
suffix='%s_%s.dat'%(model.get_str(),i)
filename_mps='data/mps_'+suffix
filename_eng='data/eng_'+suffix
mps=state2MPS(EV[:,i],sitedim=2,l=0)
mps.save(filename_mps)
savetxt(filename_eng,Emin)
def solve_update(model,expander,k=1):
'''
Solve using chain updates.
'''
H_serial=op2collection(op=model.hgen.get_opH())
ion()
#H_serial.show_advanced()
t0=time.time()
if isinstance(expander.evolutor,NullEvolutor):
H=get_H(H=H_serial,hgen=expander)
Emin,Evec=eigsh(H,k=k,which='SA',tol=1e-12)
else:
H2,bm2=get_H_bm(H=H_serial,hgen=expander,bstr='P')
print bm2.check_blockdiag(H2)
H_even=bm2.lextract_block(H2,0)
H_odd=bm2.lextract_block(H2,1)
Emin_even,Evec_even=eigsh(H_even,k=k,which='SA',tol=1e-12)
Emin_odd,Evec_odd=eigsh(H_odd,k=k,which='SA',tol=1e-12)
#Emin,Evec=eigsh(H2,k=k,which='SA',tol=1e-12)
t1=time.time()
print 'The Ground State Energy for model %s is %s(even),%s(odd): diff -> %s, Elapse -> %s.'%(
model,Emin_even.min(),Emin_odd.min(),Emin_odd.min()-Emin_even.min(),t1-t0)
return Emin_even,Evec_even,Emin_odd,Evec_odd
