Superposition

Calculates superposition of curves in a specified range

The function returns the y values of the superposition of several curves at specified x values.
yv = superposition(xv,x1,y1,x2,y1,x3,y3);

will return the y values for the superposition of the curves specified by the vectors (x1,y1), (x2,y2), (x3,y3) at the x values specified in xv.

The first argument is a vector of x values at which the y values need to be calculated. The user can specify as many pairs of xn,yn values as they like. These curves need not have the same range or number of points. Obviously, the pair xn and yn need to have the same number of points. When the first argument has points that lie outside all the specified curves, the y values is assumed to be zero.