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delta_max and fix cabs2

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Ian Jauslin
2023-06-13 18:45:19 -04:00
parent 4ffbe1e978
commit 34b7a0c277
7 changed files with 166 additions and 20 deletions
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26
src/navier-stokes.c
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@@ -17,13 +17,12 @@ limitations under the License.
#include "constants.cpp"
#include "io.h"
#include "navier-stokes.h"
#include "complex_tools.h"
#include <math.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#define CABS2(x) ((__real__ x) * (__real__ x) + (__imag__ x) * (__imag__ x))
// compute solution as a function of time
int uk(
int K1,
@@ -36,6 +35,7 @@ int uk(
double L,
double adaptive_tolerance,
double adaptive_factor,
double max_delta,
_Complex double* u0,
_Complex double* g,
bool irreversible,
@@ -94,7 +94,7 @@ int uk(
ns_step_rkf45(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, true);
} else if (algorithm==ALGORITHM_RKDP54) {
// only compute k1 on the first step
ns_step_rkdp54(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, &tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, time==starting_time);
ns_step_rkdp54(u, adaptive_tolerance, adaptive_factor, max_delta, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, &tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, time==starting_time);
} else if (algorithm==ALGORITHM_RKBS32) {
// only compute k1 on the first step
ns_step_rkbs32(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, tmp2, tmp3, &tmp4, tmp5, irreversible, time==starting_time);
@@ -144,6 +144,7 @@ int enstrophy(
double L,
double adaptive_tolerance,
double adaptive_factor,
double max_delta,
_Complex double* u0,
_Complex double* g,
bool irreversible,
@@ -203,7 +204,7 @@ int enstrophy(
ns_step_rkf45(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, true);
} else if (algorithm==ALGORITHM_RKDP54) {
// only compute k1 on the first step
ns_step_rkdp54(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, &tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, time==starting_time);
ns_step_rkdp54(u, adaptive_tolerance, adaptive_factor, max_delta, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, &tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, time==starting_time);
} else if (algorithm==ALGORITHM_RKBS32) {
// only compute k1 on the first step
ns_step_rkbs32(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, tmp2, tmp3, &tmp4, tmp5, irreversible, time==starting_time);
@@ -317,6 +318,7 @@ int quiet(
double final_time,
double nu,
double delta,
double max_delta,
double L,
double adaptive_tolerance,
double adaptive_factor,
@@ -361,7 +363,7 @@ int quiet(
ns_step_rkf45(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, true);
} else if (algorithm==ALGORITHM_RKDP54) {
// only compute k1 on the first step
ns_step_rkdp54(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, &tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, time==starting_time);
ns_step_rkdp54(u, adaptive_tolerance, adaptive_factor, max_delta, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, &tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, irreversible, time==starting_time);
} else if (algorithm==ALGORITHM_RKBS32) {
// only compute k1 on the first step
ns_step_rkbs32(u, adaptive_tolerance, adaptive_factor, K1, K2, N1, N2, nu, &step, &next_step, L, g, fft1, fft2, ifft, &tmp1, tmp2, tmp3, &tmp4, tmp5, irreversible, time==starting_time);
@@ -856,6 +858,7 @@ int ns_step_rkdp54(
_Complex double* u,
double tolerance,
double factor,
double max_delta,
int K1,
int K2,
int N1,
@@ -946,10 +949,13 @@ int ns_step_rkdp54(
for(ky=(kx>0 ? -K2 : 1);ky<=K2;ky++){
// difference between 5th order and 4th order
// use the norm |u_k|^2k^2 (to get a bound on the error of the enstrophy)
err+=(kx*kx+ky*ky)*CABS2((*delta)*(-71./57600*(*k1)[klookup_sym(kx,ky,K2)]+71./16695*k3[klookup_sym(kx,ky,K2)]-71./1920*k4[klookup_sym(kx,ky,K2)]+17253./339200*k5[klookup_sym(kx,ky,K2)]-22./525*k6[klookup_sym(kx,ky,K2)]+1./40*(*k2)[klookup_sym(kx,ky,K2)]));
relative+=(kx*kx+ky*ky)*(CABS2(tmp[klookup_sym(kx,ky,K2)]-u[klookup_sym(kx,ky,K2)]));
err+=(kx*kx+ky*ky)*cabs2((*delta)*(-71./57600*(*k1)[klookup_sym(kx,ky,K2)]+71./16695*k3[klookup_sym(kx,ky,K2)]-71./1920*k4[klookup_sym(kx,ky,K2)]+17253./339200*k5[klookup_sym(kx,ky,K2)]-22./525*k6[klookup_sym(kx,ky,K2)]+1./40*(*k2)[klookup_sym(kx,ky,K2)]));
//relative+=(kx*kx+ky*ky)*(CABS2(tmp[klookup_sym(kx,ky,K2)]-u[klookup_sym(kx,ky,K2)]));
relative+=(kx*kx+ky*ky)*(cabs2(u[klookup_sym(kx,ky,K2)]));
}
}
err=sqrt(err);
relative=sqrt(relative);
// compare relative error with tolerance
if(err<relative*tolerance){
@@ -959,8 +965,8 @@ int ns_step_rkdp54(
u[klookup_sym(kx,ky,K2)]=tmp[klookup_sym(kx,ky,K2)];
}
}
// next delta to use in future steps
*next_delta=(*delta)*pow(relative*tolerance/err,1./5);
// next delta to use in future steps (do not exceed max_delta)
*next_delta=fmin(max_delta, (*delta)*pow(relative*tolerance/err,1./5));
// k1 in the next step will be this k4 (first same as last)
tmp=*k1;
@@ -971,7 +977,7 @@ int ns_step_rkdp54(
else{
*delta=factor*(*delta)*pow(relative*tolerance/err,1./5);
// this will reuse the same k1 without re-computing it
ns_step_rkdp54(u,tolerance,factor,K1,K2,N1,N2,nu,delta,next_delta,L,g,fft1,fft2,ifft,k1,k2,k3,k4,k5,k6,tmp,irreversible,false);
ns_step_rkdp54(u,tolerance,factor,max_delta,K1,K2,N1,N2,nu,delta,next_delta,L,g,fft1,fft2,ifft,k1,k2,k3,k4,k5,k6,tmp,irreversible,false);
}
return 0;