- Comp-phys-alps-users - lists.phys.ethz.ch

Green's function measurement in the loop and directed loop codes
by Francisco Cordobés 01 Jan '13

01 Jan '13

Hello, I was wondering what is the definition that that the loop and directed loop code return when the options: 'MEASURE[Correlations]' : True, 'MEASURE[Structure Factor]' : True, 'MEASURE[Green Function]' : True, Because I haven't been able to find them and I would like to know what they are and more importantly what prefactors it has or it hasn't. Thank you very much, Francisco Cordobes

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4 point correlations
by "Michał Maik" 31 Dec '12

31 Dec '12

Hi, I was wondering if there was a way to calculate any 4 point correlation functions. I am interested in calculating: <a_dag(i) a_dag(i) a(j) a(j)> I would like to look at pair superfliudity and these correlation functions would be very useful. As a side question, is there a way to use the winding numbers from the worms code output to study this effect? Thank you. Best Michal Maik

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Fwd: string order parameter in ALPS
by Synge Todo 31 Dec '12

31 Dec '12

Dear ALPS Developers, Can anyone tell him how to measure the string order parameter in the ALPS exact diagonalization code, or in the ALPS DMRG code? Best, Synge Begin forwarded message: > 差出人（再送）: wistaria(a)ap.t.u-tokyo.ac.jp > 差出人: hamid mosadegh <hamid.mosadegh(a)gmail.com> > 件名: Re: string order parameter in ALPS > 日時: 2012年11月27日 14:30:20 JST > 宛先: Synge Todo <wistaria(a)comp-phys.org> > > Dear Professor Todo > > Do you know any codes or libraries to evaluate string order for fermion Hubbard. > If there is any code, I think i must write it myself. > Is it possible to access to eigenvectors calculated using ALPS. > If I have these eigenvectors, i can evaluate string order. > > Thanks for attentions and good answers.

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question about ALPS
by hamid 31 Dec '12

31 Dec '12

Dear ALPS user is it possible to define a distance dependent terms to Hamiltonians ,like this term, V/|i-j| I try to define this term but the program can not evaluate i & j. thanks in advance

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pyalps functions description
by Deepak Iyer 30 Dec '12

30 Dec '12

Hi New user here. I've been looking for some docs where there is a complete list of all the pyalps functions with descriptions. Also, is there some place I can find a list of all the hardcoded measurements, etc.? Thanks! Deepak

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Import Error for ALPS on Windows 7
by Jay Deep Sau 29 Dec '12

29 Dec '12

Hi, I am trying to install ALPS on 64 bit Windows 7. I followed the following steps: (1) I installed vistrails from the binary executable. (2) I then downloaded and installed ALPS (both from the main binary package and also the nightly snapshot) and also the ALPS vistrails binary package. (3) I set the paths manually to add C:\Program Files\Vistrails\vistrails\Python27_64\;C:\Program Files\Vistrails\vistrails\Python27_64\lib\;C:\Program Files\ALPS\bin\; so that vispython and python can be run from the command prompt. (4) I copied the tutorial directory to my Desktop. (5) I then entered the tutorial directory and executed test_py.py using python. The resulting pytest.log was as follows: >>>>>>>>>>>>>>>>> dmft-02-hybridization\tutorial2a.py: Traceback (most recent call last): File "tutorial2a.py", line 27, in <module> import pyalps from ngs import * File "C:\Program Files\VisTrails\vistrails\Python27_64\lib\site-packages\pyalps\ngs.py", line 61, in <module> from pyngsobservable_c import createRealObservable #remove this with new ALEA! ImportError: cannot import name createRealObservable >>>>>>>>>>>>>>>>>>>>>>>>>>>> I got a similar error when I typed import pyalps in vispython. Any suggestions on what I did wrong would be great. thanks, Jay Deep Sau.

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error during install - alps 2.1.1
by Mateusz Łącki 29 Dec '12

29 Dec '12

Dear All, I am trying to install alps 2.1.1 - perhaps this will sove "Avoided problem" problem in my worm calculation. So far I haveproblems in setuping lapack. Installation of alps 2.0.2 took a week altogether to set up an modify the configfiles, but I have read that thenew version has updated installer so I suppose "old" tricks are just notappropriate. I wish to report I am stuck with: -- Using intel/mkl library: /opt/intel/composer_xe_2011_sp1.7.256/mkl CMake Error at config/FindLapack.cmake:43 (STRING): string sub-command REGEX, mode REPLACE needs at least 6 arguments total to command. Call Stack (most recent call first): CMakeLists.txt:304 (find_package) This is FindLapack.cmake: 39 IF($ENV{MKL} MATCHES "mkl") 40 MESSAGE(STATUS "Using intel/mkl library: $ENV{MKL}") 41 #look for the path where the mkl is installed 42 STRING(REGEX MATCHALL "[-][L]([^ ;])+" MKL_PATH_WITH_PREFIX "$ENV{MKL}") 43 STRING(REGEX REPLACE "[-][L]" "" MKL_PATHS ${MKL_PATH_WITH_PREFIX}) 44 ENDIF($ENV{MKL} MATCHES "mkl") "CMakeLists.txt:304" is a bigger mystery as there are plenty of those files, butonly two of them contain line 304: *********** ./alps/CMakeLists.txt ********* 300 301 # Lapack 302 if (NOT ALPS_FOR_VISTRAILS) 303 if (NOT LAPACK_FOUND) 304 find_package(Lapack) 305 endif (NOT LAPACK_FOUND) 306 if (LAPACK_FOUND) 307 set(ALPS_HAVE_LAPACK 1) 308 set(ALPS_HAVE_BLAS 1) 309 endif(LAPACK_FOUND) *********** ./alps/src/boost/CMakeLists.txt ********* 300 set_target_properties(boost PROPERTIES COMPILE_DEFINITIONS BOOST_THREAD_BUILD_LIB=1) 301 endif(BUILD_SHARED_LIBS) 302 endif(WIN32) 303 304 if (NOT ALPS_BUILD_SOURCE) 305 if(MSVC) 306 get_target_property(LIB_NAME ${ALPS_BOOST_LIBRARY_NAME} LOCATION) 307 add_custom_command(TARGET ${ALPS_BOOST_LIBRARY_NAME} POST_BUILD 308 COMMAND ${CMAKE_COMMAND} -E copy ${LIB_NAME} ${PROJECT_BINARY_DIR}/bin) 309 endif(MSVC) Somehow i feel that the first one is the right one. My envs: lacki@mieczyslaw:~/alps-2.1.1-r6176-src $ echo $MKL /opt/intel/composer_xe_2011_sp1.7.256/mkl Regards, Mateusz Łącki

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worm and Floating point exception
by Mateusz Łącki 21 Dec '12

21 Dec '12

Dear All I am using Worm to make some easy simulation with RESTRICT_MEASUREMENTS[N]=30 I understand that: If I set up the chemical potential correctly, then the MC algorithm encounters enough trajectories with N=30 and the output files contain resuls averagen only over trajectories with N=30 - approximation of the canonical ensemble. This is confirmed by user-experience and my weak recollecion of advide I have received here about oen year ago. But if I set the chemical potential wrongly then the average number of particles from the Grand canonical point of view is for example 45, and there are not enough (maybe even 0) trajectories to sample with N=30. In this case the output files contain somethink that makes the following python "result getter": ********************** get.py *********************** import pyalps import sys rf=pyalps.getResultFiles(prefix=sys.argv[1]) data = pyalps.loadMeasurements(rf) obl=pyalps.loadObservableList(rf) ******************************************************* behave rude: it says Floating point exception. and quits (even if only one of let say 500 output files is corrupt). Of course adjusting the chemical pontential is the key, but this seems to be complicated in a case where the phase diagram is complicated (I would have to do some form of extrapolation or binary search to get the right mu). On the other hand I see no other way to solve it. Another way to deal with that is to generate input files containing only one set of input parameters - this way each datapoint has its own prefix. It is not complicated, but somehow contrary to the idea behind the current format of the input data. Morover it is likely to make a bookkeeping mess. I have two questions: 1. is there a way to read these "faulty", "undersampled" ouput files without "Floating point exception." (I could then set up calculations for let say 10 different values of mu an choose mu that gave the closes answer - the simplest to code). 2. is there some easy way to make the MC autoadjust the chemical potential ? Regards, Mateusz Lacki

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code for heisenberg model on fcc lattice
by sh po 17 Dec '12

17 Dec '12

Dear friends. I would appreciate if you could help me with using classic montecarlo simulation for fcc lattice on Heisenberg hamiltonian with s=1 and H=SIGMA Jij Si.Sj and Jij is just sum over nearest neibours.Would you mind telling me step by step that what should I do and exactly which codes I must use for this purpose?Its the first time I wanna use Alps and I dont know the steps of working with it. Many thanks for your helps. I would appreciate your immediate attention to this matter.

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Changing code in spinmc
by Kourosh Sartipi 17 Dec '12

17 Dec '12

Hi everyone. We wanted to change the code to do some more calculations for nearest neighbor in spinmc. So far I've tracked down the problem to the file alps/applications/mc/spins/localupdate.h. We've also added the edge type for nearest neighbour in xml file defining the unit lattice. The problem is that getting edge type for the graph always returns zero. Can you please help me find our how should we track down the problem? Getting the edge type would be like this: int edgeType = boost::get(alps::edge_type_t(), graph, *iter); // iter is out_edge_iterator but the return value is always zero. (executing the exact same code for when the library parses the xml file produces the correct results. namely in file alps/src/alps/lattice/unitcell.c) Yours, Kourosh

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