www.pudn.com > geometric.rar > poly2d.m, change:2004-08-13,size:3151b

function [xgrid,ygrid,zgrid]=poly2d(coeff,order,xcoord,ycoord)  % compute a 2-D polynomial and return gridded values % % [xgrid,ygrid,zgrid]=poly2d(coeff,order,xcoord,ycoord) % % coeff =  a vector of polynomial coefficients (generated by polysurf) % order = order of the 2D polynomial % xcoord = row vector of x coordinates labeling the columns of the output %         matrix % ycoord = column vector of y coordinates labeling the rows of the output %         matrix % zgrid = output matrix of size (length(ycoords), length(xcoords)) containing  %	the polynomial function values at the specified grid locations % xgrid = output matrix of size (length(ycoords), length(xcoords)) containing  %	the xcoordinates at the specified grid locations % ygrid = output matrix of size (length(ycoords), length(xcoords)) containing  %	the ycoordinates at the specified grid locations %         % by G.F. Margrave, March 1993 % % NOTE: It is illegal for you to use this software for a purpose other % than non-profit education or research UNLESS you are employed by a CREWES % Project sponsor. By using this software, you are agreeing to the terms % detailed in this software's Matlab source file.   % BEGIN TERMS OF USE LICENSE % % This SOFTWARE is maintained by the CREWES Project at the Department % of Geology and Geophysics of the University of Calgary, Calgary, % Alberta, Canada.  The copyright and ownership is jointly held by  % its author (identified above) and the CREWES Project.  The CREWES  % project may be contacted via email at:  crewesinfo@crewes.org %  % The term 'SOFTWARE' refers to the Matlab source code, translations to % any other computer language, or object code % % Terms of use of this SOFTWARE % % 1) Use of this SOFTWARE by any for-profit commercial organization is %    expressly forbidden unless said organization is a CREWES Project %    Sponsor. % % 2) A CREWES Project sponsor may use this SOFTWARE under the terms of the  %    CREWES Project Sponsorship agreement. % % 3) A student or employee of a non-profit educational institution may  %    use this SOFTWARE subject to the following terms and conditions: %    - this SOFTWARE is for teaching or research purposes only. %    - this SOFTWARE may be distributed to other students or researchers  %      provided that these license terms are included. %    - reselling the SOFTWARE, or including it or any portion of it, in any %      software that will be resold is expressly forbidden. %    - transfering the SOFTWARE in any form to a commercial firm or any  %      other for-profit organization is expressly forbidden. % % END TERMS OF USE LICENSE  % generate the xgrid matrix xgrid = ones(length(ycoord),1)*xcoord;  %generate the ygrid matrix ygrid = ycoord*ones(1,length(xcoord));  %generate the 2-D Vandermonde matrix of order=order numcols = sum( 1:order+1 );  V = zeros(length(xgrid(:)),numcols);    colcount = 1; for n=order:-1:0    for m=0:n          V(:,colcount) = (xgrid(:).^(n-m)).*(ygrid(:).^m);          colcount=colcount+1;    end end  % compute zgrid by matrix multiplication  zgrid = V*coeff;  zgrid = reshape(zgrid,length(ycoord),length(xcoord));