05 Aug 2004
18 Nov 2004)
Vectorized fit of vectors to columns of a matrix.
function V = polyfic(x,y,ORD)
% Matlab function POLYFIT(x,y,ORD) allows only the same size of
% x and y inputs. If x is a vector of N elements, and
% size(y) =[N, M], and one needs to fit each column of y with a polynomial,
% POLYFIT can only be used in connection with some loop FOR, WHILE etc.
% This essentially decreases the practical power of MATLAB, and can become quite
% nasty, especially in the case of big matrices (image analysis: tyoically 512*512).
% Program POLYFIC allows to fit colomns, using the power of matrix operations, which
% leads to acceleration 20 to 80 times (512*512, ORDers 1:15)
%POLYFIC = POLYnomial FIT of Columns: generalization of POLYFIT
% Fits polynomials of degree ORD to columns of data.
% V = polyfic(x,y,ORD)
%Input: x = vector of independent variable
% y = data
% ORD = polynomial order (ORD=3 for cubic)
% V = polynomials in columns, matrix ORD+1 * nColumns(y)
% See also: POLYVAC
%Vassili Pastushenko Aug. 2 2004
x=x(:); %Make column of x;