def FindEigenvalues(**args):
"""
Finds the eigenvalues of the system specified by **args,
by using pIRAM or ARPACK
"""
prop = SetupProblem(**args)
tempPsi = prop.GetTempPsi()
solver = pyprop.ArpackSolver(prop)
solver.Solve()
PrintOut(solver.Solver.GetEigenvalues().real)
#test if the find eigenvectors are really eigenvectors
for i in range(len(solver.Solver.GetEigenvalues())):
solver.SetEigenvector(prop.psi, i)
tempPsi.GetData()[:] = 0
prop.MultiplyHamiltonian(tempPsi)
n1 = tempPsi.GetNorm()
n2 = prop.psi.GetNorm()
lindep = prop.psi.InnerProduct(tempPsi) / (n1 * n2)
E = prop.GetEnergyExpectationValue()
PrintOut("E = %f, cos(theta) = %f" % (E, abs(lindep)))
#Propagate the eigenstate to see if it remains in the same state
#args['silent'] = True
#args['initPsi'] = prop.psi
#Propagate(**args)
return solver
def FindEigenvalues(useArpack=False, **args):
prop = SetupProblem(**args)
if useArpack:
solver = pyprop.ArpackSolver(prop)
else:
solver = pyprop.PiramSolver(prop)
solver.Solve()
print solver.GetEigenvalues()
return solver
def GetH2Groundstate(**args):
assert("configFile" not in args)
args["configFile"] = "config.ini"
args["eigenvalueCount"] = 1
prop = SetupProblem(**args)
solver = pyprop.ArpackSolver(prop)
solver.Solve()
E = solver.GetEigenvalues()[0]
solver.SetEigenvector(prop.psi, 0)
return E, prop.psi
def FindEigenstates(useARPACK=False, **args):
"""
Uses pIRAM to find the the lowest eigenvectors of the
problem specified in **args
"""
prop = SetupProblem(**args)
#use custom initial residual if provided
initialResidual = args.get("initialResidual")
if initialResidual != None:
prop.psi.GetData()[:] = initialResidual.GetData()
#find eigenstates
solver = None
if useARPACK:
solver = pyprop.ArpackSolver(prop)
else:
solver = pyprop.PiramSolver(prop)
solver.Solve()
return solver
def CreateArpackSolver(**args): prop = SetupProblem(**args) solver = pyprop.ArpackSolver(prop) solver.Solve() return prop, solver