Comp-phys-alps-users

comp-phys-alps-users@lists.phys.ethz.ch

October 2018

7 participants
12 discussions

Why are mps_optim and dmrg different in <Sy> here after COMPLEX enabled?
by adfws 17 Oct '18

17 Oct '18

Hi everyone, I'm wondering if I can do some calculation with Sy in my spin 1/2 chain. Eventually I enabled COMPLEX to be 1, which sufficed me to have I(1i in matlab) in model xml files. There my H=sum(Sy(i)) for spin 1/2 chain with 4 sites. So the ground state is simply the case when all spin point to y down. Energy -0.5*4=-2 and all site measurements with Sy=-0.5. The question is that this is perfect with dmrg but not mps_optim, if I just change 'dmrg' in python script to 'mps_optim' <Sy> changes. My result is as follows: dmrg result: [[-0.5 -0.5 -0.5 -0.5]] mps_optim result: [[ 0. +1.54555976e-16j 0. +2.35922393e-16j 0. +9.39602206e-16j 0. +9.38558145e-32j]] Both get identical right energy value -2 but inconsistent in <Sy>. Great complex number result in MPS. Is there something I can do to make it right? All files are here: https://gitee.com/whitesnow1970/learn-Python-in-alps/tree/master/share LiuBiao ll070616(a)126.com

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error in compilation
by benoît grémaud 04 Oct '18

04 Oct '18

Dear All, I am trying to install alps on a new linux machine fedora 28. Linux 4.18.10-200.fc28.x86_64 g++ is as follows: g++ (GCC) 8.1.1 20180712 (Red Hat 8.1.1-5) I've tried different sources (including boost): 2.2.b4, 2.2.b5 and 2.3.0 and also the latest snapshot. all versions fail compiling at the same point: Building CXX object src/alps/CMakeFiles/alps.dir/alea/observablefactory.C.o In file included from /home/gremaud/alps/alps/src/alps/alea/histogrameval.h:36, from /home/gremaud/alps/alps/src/alps/alea/observablefactory.C:38: /home/gremaud/alps/alps/src/alps/alea/histogram.h: In member function ‘alps::HistogramObservable<T>::const_iterator alps::HistogramObservable<T>::rbegin() const’: /home/gremaud/alps/alps/src/alps/alea/histogram.h:88:59: error: could not convert ‘((const alps::HistogramObservable<T>*)this)->alps::HistogramObservable<T>::histogram_.std::vector<unsign ed int>::rbegin()’ from ‘std::vector<unsigned int>::reverse_iterator’ {aka ‘std::reverse_iterator<__gnu_cxx::__normal_iterator<unsigned int*, std::vector<unsigned int> > >’} to ‘alps::His togramObservable<T>::const_iterator’ {aka ‘__gnu_cxx::__normal_iterator<const unsigned int*, std::vector<unsigned int> >’} const_iterator rbegin() const { return histogram_.rbegin();} ~~~~~~~~~~~~~~~~~^~ /home/gremaud/alps/alps/src/alps/alea/histogram.h: In member function ‘alps::HistogramObservable<T>::const_iterator alps::HistogramObservable<T>::rend() const’: /home/gremaud/alps/alps/src/alps/alea/histogram.h:90:55: error: could not convert ‘((const alps::HistogramObservable<T>*)this)->alps::HistogramObservable<T>::histogram_.std::vector<unsign ed int>::rend()’ from ‘std::vector<unsigned int>::reverse_iterator’ {aka ‘std::reverse_iterator<__gnu_cxx::__normal_iterator<unsigned int*, std::vector<unsigned int> > >’} to ‘alps::Histo gramObservable<T>::const_iterator’ {aka ‘__gnu_cxx::__normal_iterator<const unsigned int*, std::vector<unsigned int> >’} const_iterator rend() const { return histogram_.rend();} The same versions were perfectly compiling a while ago on fedora 27 and centos 7. I've also tried without boost sources but the installed one from fedora but it didn't work as well. Can you help me? thanks Best regards, Benoît -------------------- Researcher at CNRS, Centre de Physique Théorique (Marseille, France) and UMI MajuLab (Singapore) Visiting Associate Professor at the Centre for Quantum Technologies (NUS, Singapore)

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