/* Function: rt_Lookup2D_Normal ==============================================
* Abstract:
* 2D normal lookup routine for data type of real_T
*/
real_T rt_Lookup2D_Normal (const real_T *xVals, const int_T numX,
const real_T *yVals, const int_T numY,
const real_T *zVals,
const real_T x, const real_T y)
{
int_T xIdx, yIdx;
real_T ylo, yhi;
real_T Zx0yhi, Zx0ylo, xlo, xhi;
real_T corner1, corner2;
xIdx = rt_GetLookupIndex(xVals,numX,x);
xlo = xVals[xIdx];
xhi = xVals[xIdx+1];
yIdx = rt_GetLookupIndex(yVals,numY,y);
ylo = yVals[yIdx];
yhi = yVals[yIdx+1];
corner1 = *(zVals + xIdx + (numX * yIdx));
corner2 = *(zVals + (xIdx+1) + (numX * yIdx));
Zx0ylo = INTERP(x, xlo, xhi, corner1, corner2);
corner1 = *(zVals + xIdx + (numX * (yIdx+1)));
corner2 = *(zVals + (xIdx+1) + (numX*(yIdx+1)));
Zx0yhi = INTERP(x, xlo, xhi, corner1, corner2);
return (INTERP(y,ylo,yhi,Zx0ylo,Zx0yhi));
}
real_T rt_Lookup(const real_T *x, int_T xlen, real_T u,
const real_T *y)
{
int_T idx = rt_GetLookupIndex(x, xlen, u);
real_T num = y[idx+1] - y[idx];
real_T den = x[idx+1] - x[idx];
/* Due to the way the binary search is implemented
in rt_look.c (rt_GetLookupIndex), den cannot be
0. Equivalently, m cannot be inf or nan. */
real_T m = num/den;
return (y[idx] + m * (u - x[idx]));
}
