trefoilknot.m

来自「用matlab实现利用统计混沌方法解决非线性系统时间序列预测的问题」· M 代码 · 共 15 行

function out = trefoilknot(nbr);
% The function
% 
%       out = trefoilknot(nbr);
% 
% generates a 3-dimensional database with <nbr> elements. 
% These elements draw a trefoil knot. 

t = 2*pi*rand(nbr,1);

x = 41*cos(t) - 18*sin(t) - 83*cos(2*t) - 83*sin(2*t) - 11*cos(3*t) + 27*sin(3*t);
y = 36*cos(t) + 27*sin(t) - 113*cos(2*t) + 30*sin(2*t) + 11*cos(3*t) - 27*sin(3*t);
z = 45*sin(t) - 30*cos(2*t) + 113*sin(2*t) - 11*cos(3*t) + 27*sin(3*t);

out = [x,y,z];