PLS_Toolbox Documentation: polyinterp	< pltternf	polypls >

polyinterp

Purpose

Polynomial interpolation, smoothing, and differentiation.

Synopsis

yi = polyinterp(x,y,xi,width,order,deriv);

Description

For a M by N input matrix y with corresponding 1 by N axis vector x (the points at which the y are given) POLYINTERP estimates the M by N matrix yi which has the smoothed values of y. If the points are evenly spaced use the SAVGOL function instead. Note that y is a matrix of ROW vectors to be smoothed.

Optional inputs are xi a vector of points to interpolate to, width specifies the number of points in the filter {default = 15}, the order of the polynomial order {default = 2}, and the derivative deriv {default = 0}.

Examples

If y is a 5 by 100 matrix, x is a 1 by 100 vector, and xi is a 1 by 91 vector then polyinterp(x,y,xi,11,3,1) gives the 5 by 91 matrix of first-derivative row vectors resulting from an 11-point cubic interpolation to the 91 points in xi.

See Also

baseline, lamsel, mscorr, savgol, stdfir