software/Nstrophy
1
Fork 0
Code Issues Pull Requests Releases Activity

RKF45: use fourth order instead of fifth

Browse Source
This commit is contained in:
Ian Jauslin 2023-05-17 16:58:13 -04:00
parent f57cc317ac
commit 5224b9052f
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/navier-stokes.c
View File

@ -712,7 +712,7 @@ int ns_step_rkf45(
// difference between 5th order and 4th order // difference between 5th order and 4th order
err+=cabs((*delta)*(1./360*k1[klookup_sym(kx,ky,K2)]-128./4275*k3[klookup_sym(kx,ky,K2)]-2197./75240*k4[klookup_sym(kx,ky,K2)]+1./50*k5[klookup_sym(kx,ky,K2)]+2./55*k6[klookup_sym(kx,ky,K2)])); err+=cabs((*delta)*(1./360*k1[klookup_sym(kx,ky,K2)]-128./4275*k3[klookup_sym(kx,ky,K2)]-2197./75240*k4[klookup_sym(kx,ky,K2)]+1./50*k5[klookup_sym(kx,ky,K2)]+2./55*k6[klookup_sym(kx,ky,K2)]));
// next step // next step
tmp[klookup_sym(kx,ky,K2)]=(*delta)*(16./135*k1[klookup_sym(kx,ky,K2)]+6656./12825*k3[klookup_sym(kx,ky,K2)]+28561./56430*k4[klookup_sym(kx,ky,K2)]-9./50*k5[klookup_sym(kx,ky,K2)]+2./55*k6[klookup_sym(kx,ky,K2)]); tmp[klookup_sym(kx,ky,K2)]=(*delta)*(25./216*k1[klookup_sym(kx,ky,K2)]+1408./2565*k3[klookup_sym(kx,ky,K2)]+2197./4104*k4[klookup_sym(kx,ky,K2)]-1./5*k5[klookup_sym(kx,ky,K2)]);
relative+=cabs(tmp[klookup_sym(kx,ky,K2)]); relative+=cabs(tmp[klookup_sym(kx,ky,K2)]);
} }
} }