June 2012 - Comp-phys-alps-users

Inconsistent comment in generate_spline_matrix in the DMFT folder
by Kuangshing Chen 21 Jul '15

21 Jul '15

Hi, The function generate_spline_matrix in fouriertransform.C in the dmft folder shows the comments as follows: // A is the matrix whose inverse defines spline_matrix // // 6 6 // 1 4 1 // 1 4 1 // A = ... // // 1 4 1 // -2 0 0 2 However, the following codes, dense_matrix A = 4*dt/6.*boost::numeric::ublas::identity_matrix<double>(Np1); for (int i=1; i<Np1-1; i++) { A(i,i-1) = dt/6.; A(i,i+1) = dt/6.; } A(0,0) = 1.; A(0, Np1-1) = 1.; A(Np1-1, 0) = -2.*dt/6.; A(Np1-1, 1) = -1.*dt/6.; A(Np1-1, Np1-2) = 1*dt/6.; A(Np1-1, Np1-1) = 2*dt/6.; the red lines will make the matrix looks like // 6 6 // 1 4 1 // 1 4 1 // A = ... // // 1 4 1 // -2 *-1* *1* 2 Is the comment correct or the code correct? Any reference for this algorithm? Thank you, Kuang-Shing Chen

5 25

ALPS 2.0.1 released
by Matthias Troyer 19 Sep '12

19 Sep '12

Dear ALPS users, ALPS 2.0.1 has been released. This is the version included with the ALPS paper: B. Bauer et al., J. Stat. Mech. (2011) P05001, which is available at : http://www.iop.org/EJ/abstract/1742-5468/2011/05/P05001 .Besides references to this paper, this release contains many minor bug fixes. The MacOS X 10.5 binary release will be uploaded shortly. The others are ready for download. Best regards Matthias Troyer

4 33

entanglement entropy in DMRG
by grover＠berkeley.edu 21 Jun '12

21 Jun '12

Hi All! I am very new to ALPS and trying to use it for DMRG of simple one-dimensional models. I would be thankful if someone can point out to me the python command in ALPS to access entanglement entropy (or better, the entanglement spectrum) that is generated at the end of DMRG convergence. Thank you, Sincerely, Tarun ps: I am assuming that the entanglement entropy in ALPS DMRG corresponds to the partition that divides the system into two-halves.

2 1

alpspython
by Tadeusz Wasiutyński 11 Jun '12

11 Jun '12

Hello, it would be very convenient for me to analyse results on my laptop by alpspython without compiling the whole ALPS package. Is there an easy way to grub necessary files? Regards Tadeusz Wasiutynski

2 1

fitting of experimental data
by Dmitry 08 Jun '12

08 Jun '12

Dear all, in the description of ALPS there is a note about the possibility of experimental data fitting. Unfortunately, I can't find in tutorials and documentation the way how to fit, for example, experimental susceptibility data with the simulations from ALPS. In the code I've found just fit_wrapper function. Should I use it (or another) for parameter optimization or it's need to write own optimizer? Thanks in advance.

2 1

Which XML parser the ALPS use?
by Bo Li 01 Jun '12

01 Jun '12

Dear ALPS developers, The Hamiltonian in ALPS is defined by a XML file. Which XML parser the ALPS use, Xerces-c++-XML parser or Boost-c++-XML parser? Regards, Bo Li

2 2