stcol.m

演示matlab曲线拟和与插直的基本方法

% STCOL   揰嵼偡傞曄姺慖揰峴楍
%
% COLMAT = STCOL(CENTERS, X, TYPE) 偼丄psi_j 偲 n 偑丄STMAK 偱婰弎偝傟偰
% 偄傞傛偆偵丄CENTERS 偲暥帤楍 TYPE 偵埶懚偡傞丄(i,j) 偺梫慺偑
%
%      psi_j( X(:,i) ),   i=1:size(X,2),  j=1:n ,
%
% 偲側傞峴楍傪弌椡偟傑偡丅
%
% CENTERS 偲 X 偼丄摨偠峴悢傪傕偮峴楍偱側偗傟偽側傝傑偣傫丅
%
% TYPE 偺僨僼僅儖僩偼 'tp' 偱丄偙偺僨僼僅儖僩偵懳偟偰丄n 偼 size(CENTERS,2) 
% 偱丄娭悢 psi_j 偼丄偮偓偺傛偆偵梌偊傜傟偰偄傑偡丅
%
%      psi_j(x) := psi( x - CENTERS(:,j) ),   j=1:n,
%
% 偙偙偱丄psi 偼丄thin-plate僗僾儔僀儞婎掙娭悢偱偁傝丄
%
%      psi(x) := |x|^2 log |x|^2 
%
% 偱偡丅偨偩偟丄|x| 偼丄儀僋僩儖 x 偺儐乕僋儕僢僪(Euclidean)僲儖儉傪
% 帵偟偰偄傑偡丅
%
% COLMAT = STCOL(..., 'tr') 偼丄STCOL(...) 偺揮抲傪弌椡偟傑偡丅
%
% 峴楍 COLMAT 偼丄慄宍僔僗僥儉
%
%      sum_j a_j psi_j(X(:,i))  =  y_i,    i=1:size(X,2)
% 
% 偺學悢峴楍偱偡丅娭悢 f := sum_j a_j psi_j 偑丄偡傋偰偺 i 偵偮偄偰
% 僒僀僩 X(:,i) 偱抣 _i 傪曗娫偡傞偵偼丄f 偺學悢 a_j 偑偙偺幃傪枮懌偟偰
% 偄側偗傟偽側傝傑偣傫丅
%
% 椺戣
%      a = [0,2/3*pi,4/3*pi]; centers = [cos(a), 0; sin(a), 0];
%      [x1,x2] = ndgrid(linspace(-2,2,45)); 
%      xx = [x1(:) x2(:)].';
%      coefs = [1 1 1 -3.5];
%      y = reshape( coefs*stcol(centers,xx,'tr'), size(x1));
%      surf(x1,x2,y), view([240,15]), axis off
%   偼丄thin-plate僗僾儔僀儞婎掙娭悢偺4偮偺揰嵼偡傞曄姺 
%   psi(x-centers(:,j))丆j=1:4, 偺廳傒晅偒偺榓傪昡壙偟丄僾儘僢僩偟傑偡丅
%
% 嶲峫 STMAK, STBRK, STVAL, SPCOL.


%   Copyright 1987-2004 C. de Boor and The MathWorks, Inc.