solver.diag.dat

Introduction

The solver.diag.dat file is used to store the diagram configurations of the perturbation expansion series. Owing to the limitation of disk capacity and computational efficiency, it is impossible to save all of the visited diagram configurations. Consequently we only save the current diagram configurations every nwrite Monte Carlo step. Namely, the frequency for writing diagram configurations is controlled by the nwrite parameter. See also nwrite for more details.

Format

The solver.diag.dat file consists many blocks. The blocks are separated by two blank lines. A typical block looks like as follows:

>> cur_iter:   1 tot_iter:  20
>> cur_diag:   4 tot_diag:1000
# flvr:   1 rank:   2
   1      6.49617550      0.35585709
   1      7.30348648      7.28301304
# flvr:   2 rank:   1
   2      0.43805150      6.89040598

Here cur_iter means current iteration number, tot_iter the total iteration number, cur_diag the index of the current diagram configuration, tot_diag the total number of diagram configurations. Actually, we have

\[\text{tot\_diag} = \frac{\text{nsweep}}{\text{nwrite}}.\]

Next, the positions for creator/destroy operators are given for all orbitals (flavors).

column 1: the index of orbitals.

column 2: $\tau_s$, the imaginary-time points for creator operators

column 3: $\tau_e$, the imaginary-time points for destroy operators

We can utilize the data in the solver.diag.dat file to produce animation movie. A block can be used to generate one frame in the movie.

Code

The corresponding Fortran code block for the writing of solver.diag.dat file is as follows:

! write the snapshot
! open data file: solver.diag.dat
     open(mytmp, file='solver.diag.dat', form='formatted', status='unknown', position='append')

! write diagram info
     write(mytmp,'(2(a,i4))') '>> cur_iter:', iter, ' tot_iter:', niter
     write(mytmp,'(2(a,i4))') '>> cur_diag:', cstep/nwrite, ' tot_diag:', nsweep/nwrite

! write the position of operators
     do i=1,norbs
         write(mytmp,'(2(a,i4))') '# flvr:', i, ' rank:', rank(i)
         do j=1,rank(i)
             write(mytmp,'(i4,2f16.8)') i, time_s( index_s(j, i), i ), time_e( index_e(j, i), i )
         enddo ! over j={1,rank(i)} loop
     enddo ! over i={1,norbs} loop

! write two blank lines
     write(mytmp,*)
     write(mytmp,*)

! close data file
     close(mytmp)

You can use the u_movie.py script to visualize the diagram configurations in the solver.diag.dat file. See also script/u_movie.py for more details.