boogkrom.m

等高线拟合源代码（matlab源码）

function [xi, yi, kappa] = boogkrom(ax, bx, cx, dx, ay, by, cy, dy, u);

% function [xi, yi, kappa] = boogkrom(ax, bx, cx, dx, ay, by, cy, dy, u);
% Calculates function values (xi,yi) and curvature kappa
%
% ax, ... , dy : variables of parametric spline
% u : parameter in functie waarvan gefit werd
%
% 21 april 1999
% Walter Verdonck,

% All the software included in this package is presented as is.
% It may be distributed freely. The author can, however, not be
% held responsible for any problems whatever.
% 
% Designed by Johan Baeten, Walter Verdonck
% Last updated: 29-03-2000
% [e-mail]



n = length(cx);

tel = 1;
aantal = 30; % # of caluclated points per interval

for k = 1:n,
          uv = linspace(u(k),u(k+1),aantal);
          du = uv -u(k);
	       xi(tel:tel+aantal-1)= ax(k)+du.*(bx(k)+du.*(cx(k)+dx(k).*du));
          yi(tel:tel+aantal-1)= ay(k)+du.*(by(k)+du.*(cy(k)+dy(k).*du)); 
          % calculations for curvature
          x1(tel:tel+aantal-1)= bx(k)+du.*(2*cx(k)+du.*3*dx(k));
          y1(tel:tel+aantal-1)= by(k)+du.*(2*cy(k)+du.*3*dy(k)); 
          telkrom(tel:tel+aantal-1)=(2*(bx(k)*cy(k)-by(k)*cx(k))+((bx(k)*dy(k)-by(k)*dx(k))+(cx(k)*dy(k)-dx(k)*cy(k))*du)*6.*du);
          tel = tel + aantal-1;
end

noemer=sqrt((x1.^2+y1.^2).^3);
kappa=telkrom./noemer;

% Is plot asked ?