Neville's algorithm to interpolate without calculating the coefficients.
|xy||It is a matrix the first column of which contains the x values, the second contains the corresponding y values. It is expected to be sorted by x.|
|return value||Interpolating polynomial.|
In comparison, the function polynLagrange calculates the coefficients, and hence is probably more efficient for many evaluation of the same interpolating polynomial.
xy = [-1,4; 4,8; 42,-88; 444, 827]; xunit = 1J; yunit = 1V; xmin = min(xy[...;0]); xmax = max(xy[...;0]); eps = (xmax-xmin)/200; xmin -= 2*eps; xmax += 2*eps; x = (xmin..eps..xmax)*xunit; y = (@(x) polynInterp(xy * [xunit,0;0,yunit], x))(#x); plot(x,y)