double xi2d_interp(double rs1, double rp1, double rs2, double rp2)
{
static double **xi2d,rmax,rmin,*rsig,*rpi,**yy2d;
static int flag=1,n,prev;
int i,j,ng=20;
double dx,dy,dlogr,xsum,rs,rp,x;
if(flag || prev!=RESET_COSMOLOGY)
{
two_halo(1,1);
prev=RESET_COSMOLOGY;
n=35;
if(flag)
{
xi2d=dmatrix(1,n,1,n);
yy2d=dmatrix(1,n,1,n);
rsig=dvector(1,n);
rpi=dvector(1,n);
}
flag=0;
rmax=log(40.5);
rmin=log(0.05);
dlogr = (rmax-rmin)/(n-1);
for(i=1;i<=n;++i)
rsig[i]=rpi[i]=exp((i-1)*dlogr+rmin);
calc_xi2d(xi2d,n,rmax,rmin);
splie2(rsig,rpi,xi2d,n,n,yy2d);
}
if(rs2<0 && rp2<0)
{
splin2(rsig,rpi,xi2d,yy2d,n,n,(rs1),(rp1),&x);
return(x);
}
dx=(rs2-rs1)/ng;
dy=(rp2-rp1)/ng;
xsum=0;
for(i=1;i<=ng;++i)
for(j=1;j<=ng;++j)
{
rs=rs1+(i-0.5)*dx;
rp=rp1+(j-0.5)*dy;
splin2(rsig,rpi,xi2d,yy2d,n,n,(rs),(rp),&x);
xsum+=2*dy*rs*dx*(x);
}
xsum/=((rs2*rs2-rs1*rs1)*(rp2-rp1));
return(xsum);
}
/* The angular grid here is set such that
* it's only used for the small-r SDSS multipoles, i<=3, or r<~ 1 Mpc/h
*/
double xi2d_interp_polar(double rs1, double rs2, double phi1, double phi2)
{
static double **xi2d,rmax,rmin,*rsig,*rpi,**yy2d;
static int flag=1,n,prev;
int i,j,ng=20;
double dx,dy,dlogr,xsum,rs,rp,x,vsum,dr,dphi,phi,r;
if(flag || prev!=RESET_COSMOLOGY)
{
two_halo(1,1);
prev=RESET_COSMOLOGY;
n=15;
if(flag)
{
xi2d=dmatrix(1,n,1,n);
yy2d=dmatrix(1,n,1,n);
rsig=dvector(1,n);
rpi=dvector(1,n);
}
flag=0;
rmax=log(2.5);
rmin=log(0.05);
dlogr = (rmax-rmin)/(n-1);
for(i=1;i<=n;++i)
rsig[i]=rpi[i]=exp((i-1)*dlogr+rmin);
calc_xi2d(xi2d,n,rmax,rmin);
splie2(rsig,rpi,xi2d,n,n,yy2d);
}
rs1 = log(rs1);
rs2 = log(rs2);
dr=(rs2-rs1)/ng;
dphi=(phi2-phi1)/ng;
xsum=vsum=0;
for(i=1;i<=ng;++i)
for(j=1;j<=ng;++j)
{
r=exp(rs1+(i-0.5)*dr);
phi=phi1+(j-0.5)*dphi;
rp = r*sin(phi);
rs = r*cos(phi);
splin2(rsig,rpi,xi2d,yy2d,n,n,(rs),(rp),&x);
xsum+=sin(phi)*r*r*r*(x);
vsum+=r*r*r*sin(phi);
}
xsum/=vsum;
return(xsum);
}
/*** Returns the 2D cubic spline interpolated value ***/
double Spline::operator()(double x1pt, double x2pt) const {
double result;
if (dim!=2) error("Spline.operator(): wrong dimension (expected 2) or not initialized.");
splin2(x1, x2, f2d, d2fdxdy, N1, N2, x1pt, x2pt, &result);
return result;
}