error in measuring MPO observables

[liang]

Dear all,
I tested measuring MPO observables. I added related term in Ising model as suggested in the OSMPS_Manual, the error appears:

Execute_MPSMain TMP/Ising_Staticsg_0.0Main.nml
running with 0 1
Cannot open file named TMP/Ising_Staticsg_0.0ObsMPO_1.dat

Execute_MPSMain TMP/Ising_Staticsg_0.1Main.nml
running with 0 1
Cannot open file named TMP/Ising_Staticsg_0.1ObsMPO_1.dat

---

Do I missed some term? or what's the problem? thanks.

Best regards
Jun-Jun

---

In IsingStatics.py nothing is added but the following paragraph:
DefectDensity=mps.MPO()
DefectDensity.AddMPOTerm(Operators,'bond',['sz','sz'])
myObservables.AddObservable(Operators,DefectDensity,'MPO','DefectDensity')

---

souce file：　

import MPSPyLib as mps
import numpy as np
import matplotlib.pyplot as plt

PostProcess=False

Operators=mps.BuildSpinOperators(0.5)
Operators['sigmaz']=2*Operators['sz']
Operators['sigmax']=(Operators['splus']+Operators['sminus'])

H=mps.MPO()

H.AddMPOTerm(Operators,'bond',['sigmaz','sigmaz'],hparam='J',weight=-1.0)
H.AddMPOTerm(Operators,'site','sigmax',hparam='g',weight=-1.0)

myObservables=mps.Observables()

DefectDensity=mps.MPO()
DefectDensity.AddMPOTerm(Operators,'bond',['sz','sz'])
myObservables.AddObservable(Operators,DefectDensity,'MPO','DefectDensity')

myConv=mps.MPSConvergenceParameters(max_bond_dimension=20,max_num_sweeps=6,local_tol=1E-14)

J=1.0
glist=np.linspace(0,2,21)
parameters=[]
L=30

for g in glist:
parameters.append({
#Directories
'job_ID' : 'Ising_Statics',
'unique_ID' : 'g_'+str(g),
'Write_Directory' : 'TMP/',
'Output_Directory' : 'OUTPUTS/',
#System size and Hamiltonian parameters
'L' : L,
'J' : J,
'g' : g,
#ObservablesConvergence parameters
'verbose' : 1,
'MPSObservables' : myObservables,
'MPSConvergenceParameters' : myConv
})

MainFiles=mps.WriteFiles(parameters,Operators,H,PostProcess=PostProcess)

if not PostProcess:
mps.runMPS(MainFiles,RunDir='')

if PostProcess:
magnetizationlist=[]
Outputs=mps.ReadStaticObservables(parameters)
for Output in Outputs:
print Output['converged']
spincorrelation=Output['zz']
magnetization=np.sqrt(spincorrelation[4][27])
magnetizationlist.append(magnetization)
plt.rc('text', usetex=True)
plt.rc('font', family='serif')
plt.scatter(glist,magnetizationlist)
plt.xlabel(r"\textbf{transverse field coupling} " r"$g$",fontsize=16)
plt.ylabel(r"\textbf{Magnetization}" r"$\sqrt{\langle\sigma^\mathbf{z}4\sigma^\mathbf{z}{27}\rangle}$",fontsize=16)
plt.xlim((0,2))
plt.ylim((0,1))
plt.show()

[Anonymous]

Hi Jun-Jun,
Adding CALL AppendBaseName(ObsName,extrastub) between lines 163 and 164 in PyInterface_all_include.f90 will fix the problem. Thank you.

[Anonymous]

Hi Jun-Jun,
This is the followup of last reply. To be more specific,
Add CALL AppendBaseName(ObsName,extrastub) between
CALL AppendBaseName(ObsName,fileStub)
and
CALL AppendBaseName(ObsName,'ObsMPO_')
in the last do loop in the SUBROUTINE ReadObservables_MATRIXLIST_TYPE in the file PyInterface_all_include.f90.
Also add CALL AppendBaseName(ObsName,extrastub) to the same place in the SUBROUTINE DeallocateObservables_MATRIXLIST_TYPE in the same file. Thank you.

Daniel and Wei

[liang]

Dear Daniel and Wei,
It works well, thank you.

Best regards
Jun-Jun