sddemo.m

实现matlab很多功能的源代码

% Interactive demo of steepest descent paths on "peaks" surface.

% Roger Jang, Oct-16-1996

figure('name', 'Steepest Descent', 'NumberTitle', 'off');
%blackbg;
x=-3:.2:3;
y=-3:.2:3;
[xx,yy]=meshgrid(x,y);
zz=peaks(xx,yy);
surf(xx, yy, zz);
axis([-inf inf -inf inf -inf inf]);
colormap((jet+white)/2);
ballH = line(nan, nan, nan, 'marker', '.', 'markersize', 20, 'erase', 'xor', 'color', 'g');

segment3dH = line(nan, nan, nan, 'erase', 'none', 'color', 'r');
set(gca, 'box', 'on');

figure('name', 'Steepest Descent', 'NumberTitle', 'off');
%blackbg;
hold on;
h=pcolor(x,y,zz);
set(h, 'erase', 'none');
colormap((jet+white)/2);
shading interp;
%[px,py]=gradient(zz,.2,.2);
%quiver(x,y,-px,-py,2,'k');
[junk, contourH] = contour(xx, yy, zz, 20, 'k-');
hold off;
axis([-3 3 -3 3]); axis square; axis off;

circleH = line(nan, nan, 'marker', '.', 'erase', 'xor', 'color', 'g', 'markersize', 20);

segment2dH = line([nan nan], [nan nan], 'erase', 'none', 'color', 'r');
set(contourH, 'erase', 'none', 'color', 'w');
title('叫