| program main |
| use, intrinsic :: iso_c_binding, only: sp=>c_float, dp=>c_double |
| use iso_fortran_env |
| implicit none |
| integer*4 :: L |
| real*8 :: magne, energ, TEMP, E, DIFE, DELTA, M, SUMA, W(-8:8) |
| integer*4 :: I, J, IMC, MCTOT, MCINI, MCD, IPAS, N, SEED, NSEED, SEED0, pbc |
| integer :: genrand_int31 |
| character(100) :: NOM |
| logical :: SAVEFINALCONF |
| |
| integer :: SUMI |
| real(dp) :: SUME, SUME2, SUMM, SUMAM, SUMM2, VARE, VARM, CV, CHI |
| |
| ! This should be replaced by L but it doesn't work dynamically, so we're |
| ! setting 64 as the upper limit which should be higher than L. |
| integer*2 :: S(1:64, 1:64) |
| |
| ! Inicialitzem algunes variables sobre el problema |
| namelist /DADES/ L, NOM, TEMP, NSEED, SEED0, MCTOT, MCINI, MCD, SAVEFINALCONF |
| read(nml = DADES, unit = 5) |
| |
| N = L*L |
| |
| ! Cache dels valors de l'exponencial |
| do I = 0, 8 |
| W(I) = (2**30 - 1 + 2**30)*exp(-float(I)/TEMP) |
| enddo |
| |
| SUMI = 0 |
| SUME = 0 |
| SUME2 = 0 |
| |
| SUMM = 0 |
| SUMAM = 0 |
| SUMM2 = 0 |
| |
| do SEED = SEED0, SEED0 + NSEED - 1 |
| print *, "Seed: ", SEED |
| |
| ! Inicialitzem la matriu d'spins aleatòriament |
| call generateSpinMatrix(S, L, SEED) |
| |
| E = energ(S, L) |
| M = magne(S, L) |
| |
| ! Iterem amb el mètode de Montecarlo |
| do IMC = 1, MCTOT |
| do IPAS = 1, N |
| ! LOS LOOPS HACEN COSAS |
| I = mod(genrand_int31(), L) + 1 |
| J = mod(genrand_int31(), L) + 1 |
| SUMA = S(PBC(I - 1, L), J) + & |
| S(PBC(I + 1, L), J) + & |
| S(I, PBC(J - 1, L)) + & |
| S(I, PBC(J + 1, L)) |
| DIFE = 2*SUMA*S(I, J) |
| |
| if (DIFE > 0) then |
| DELTA = genrand_int31() |
| if (DELTA >= W(int(DIFE))) then |
| ! NO ho acceptem |
| cycle |
| endif |
| endif |
| |
| ! Sí ho acceptem: |
| S(I, J) = -S(I, J) |
| E = E + DIFE |
| M = M + 2*S(I, J) |
| enddo |
| |
| if (IMC > MCINI .and. mod(IMC, MCD) == 0) then |
| SUMI = SUMI + 1 |
| |
| SUME = SUME + E |
| SUME2 = SUME2 + E*E |
| |
| SUMM = SUMM + M |
| SUMAM = SUMAM + abs(M) |
| SUMM2 = SUMM2 + M*M |
| endif |
| enddo |
| enddo |
| |
| ! Normalitzem els promitjos |
| SUME = SUME/SUMI |
| SUME2 = SUME2/SUMI |
| SUMM = SUMM/SUMI |
| SUMAM = SUMAM/SUMI |
| SUMM2 = SUMM2/SUMI |
| VARE = SUME2 - SUME**2 |
| VARM = SUMM2 - SUMM**2 |
| CV = (SUME2 - SUME**2)/real(N*TEMP**2) |
| CHI = (SUMM2 - SUMAM**2)/real(N*TEMP) |
| |
| ! Guardem a un fiter els promitjos |
| open(unit = 13, file = "data_out/" // trim(NOM) // ".res") |
| ! Valors: L, T, <E>, <E**2>, Var(E), <M>, <|M|>, <M**2>, Var(M), C_V, CHI |
| write(13, *) L, TEMP, SUME, SUME2, VARE, SUMM, SUMAM, SUMM2, VARM, CV, CHI |
| |
| if (SAVEFINALCONF) then |
| call writeConfig(S, L, "data_out/" // trim(NOM) // ".conf") |
| endif |
| |
| ! Tanquem els fitxers de sortida |
| close(13) |
| endprogram main |