This function estimates the quasi-potential value for any x- and y-values
QPInterp(X, Y, x.bound, y.bound, surface)the value of the x to interpolate.
the value of the y to interpolate.
a two-element vector with the minimum and maximum x values used for computing the quasi-potential.
a two-element vector with the minimum and maximum y values used for computing the quasi-potential.
the surface to interpolated, from QPGlobal.
this function uses bilinear interpolation for estimattion of any x- and y-value.