void ExplForwEuler(vec &v, int Nx, int Nt, double dx, double dt){
vec v_next = zeros(Nx);
mat sol = zeros(Nx,Nt);
vec us = 1-linspace(0,1,Nx);
sol.col(0) = v+us; // Save real solution u = v + us
double dtxx = dt/(dx*dx);
for(int j=1; j<Nt; j++){
for(int i=1; i<Nx-1; i++){
v_next(i) = dtxx*v(i-1) + (1-2*dtxx)*v(i) + dtxx*v(i+1);
}
v = v_next;
sol.col(j) = v+us;
}
sol.save("ExplForwEuler.dat",raw_ascii);
}
void offset_adjust_settings(cdrom_paranoia *p, void(*callback)(long,int)){
if(p->stage2.offpoints>=10){
/* drift: look at the average offset value. If it's over one
sector, frob it. We just want a little hysteresis [sp?]*/
long av=(p->stage2.offpoints?p->stage2.offaccum/p->stage2.offpoints:0);
if(abs(av)>p->dynoverlap/4){
av=(av/MIN_SECTOR_EPSILON)*MIN_SECTOR_EPSILON;
if(callback)(*callback)(ce(p->root.vector),PARANOIA_CB_DRIFT);
p->dyndrift+=av;
/* Adjust all the values in the cache otherwise we get a
(potentially unstable) feedback loop */
{
c_block *c=c_first(p);
v_fragment *v=v_first(p);
while(v && v->one){
/* safeguard beginning bounds case with a hammer */
if(fb(v)<av || cb(v->one)<av){
v->one=NULL;
}else{
fb(v)-=av;
}
v=v_next(v);
}
while(c){
long adj=min(av,cb(c));
c_set(c,cb(c)-adj);
c=c_next(c);
}
}
p->stage2.offaccum=0;
p->stage2.offmin=0;
p->stage2.offmax=0;
p->stage2.offpoints=0;
p->stage2.newpoints=0;
p->stage2.offdiff=0;
}
}
if(p->stage1.offpoints>=10){
/* dynoverlap: we arbitrarily set it to 4x the running difference
value, unless min/max are more */
p->dynoverlap=(p->stage1.offpoints?p->stage1.offdiff/
p->stage1.offpoints*3:CD_FRAMEWORDS);
if(p->dynoverlap<-p->stage1.offmin*1.5)
p->dynoverlap= - (long)( (double)p->stage1.offmin * 1.5 );
if(p->dynoverlap<p->stage1.offmax*1.5)
p->dynoverlap = (long)( (double)p->stage1.offmax * 1.5 );
if(p->dynoverlap<MIN_SECTOR_EPSILON)p->dynoverlap=MIN_SECTOR_EPSILON;
if(p->dynoverlap>MAX_SECTOR_OVERLAP*CD_FRAMEWORDS)
p->dynoverlap=MAX_SECTOR_OVERLAP*CD_FRAMEWORDS;
if(callback)(*callback)(p->dynoverlap,PARANOIA_CB_OVERLAP);
if(p->stage1.offpoints>600){ /* bit of a bug; this routine is
called too often due to the overlap
mesh alg we use in stage 1 */
p->stage1.offpoints = (long)( (double)p->stage1.offpoints / 1.2 );
p->stage1.offaccum = (long)( (double)p->stage1.offaccum / 1.2);
p->stage1.offdiff = (long)( (double) p->stage1.offdiff / 1.2 );
}
p->stage1.offmin=0;
p->stage1.offmax=0;
p->stage1.newpoints=0;
}
}
