105 lines
1.8 KiB
C
105 lines
1.8 KiB
C
#include "init.h"
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#include "navier-stokes.h"
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#include "io.h"
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#include <stdlib.h>
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#include <math.h>
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// random initial condition
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int init_random (
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_Complex double* u0,
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double init_en,
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int K1,
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int K2,
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double L,
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int seed,
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bool irreversible
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){
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int kx,ky;
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double rescale;
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double x,y;
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srand(seed);
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// random init (set half, then the other half are the conjugates)
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for(kx=0;kx<=K1;kx++){
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for(ky=-K2;ky<=K2;ky++){
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if (kx!=0 || ky>0){
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x=-0.5+((double) rand())/RAND_MAX;
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y=-0.5+((double) rand())/RAND_MAX;
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u0[klookup_sym(kx,ky,K2)]=x+y*I;
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}
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}
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}
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if (irreversible) {
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// fix the energy
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rescale=compute_energy(u0, K1, K2);
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} else {
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// fix the enstrophy
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rescale=compute_enstrophy(u0, K1, K2, L);
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}
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for(kx=0;kx<=K1;kx++){
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for(ky=-K2;ky<=K2;ky++){
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u0[klookup_sym(kx,ky,K2)]=u0[klookup_sym(kx,ky,K2)]*sqrt(init_en/rescale);
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}
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}
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return 0;
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}
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// Gaussian initial condition
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int init_gaussian (
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_Complex double* u0,
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double init_en,
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int K1,
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int K2,
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double L,
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bool irreversible
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){
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int kx,ky;
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double rescale;
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for(kx=0;kx<=K1;kx++){
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for(ky=-K2;ky<=K2;ky++){
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u0[klookup_sym(kx,ky,K2)]=(kx*kx+ky*ky)*exp(-(kx*kx+ky*ky));
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}
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}
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if (irreversible) {
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// fix the energy
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rescale=compute_energy(u0, K1, K2);
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} else {
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// fix the enstrophy
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rescale=compute_enstrophy(u0, K1, K2, L);
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}
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for(kx=0;kx<=K1;kx++){
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for(ky=-K2;ky<=K2;ky++){
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u0[klookup_sym(kx,ky,K2)]=u0[klookup_sym(kx,ky,K2)]*sqrt(init_en/rescale);
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}
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}
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return 0;
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}
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// Initialize from file
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// txt input
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int init_file_txt (
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_Complex double* u0,
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int K1,
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int K2,
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FILE* initfile
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){
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read_u(u0, K1, K2, initfile);
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return 0;
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}
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// binary input
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int init_file_bin (
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_Complex double* u0,
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int K1,
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int K2,
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FILE* initfile
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){
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read_u_bin(u0, K1, K2, initfile);
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return 0;
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}
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