beg.m

本程序模拟GP算法处理数据的方法步骤How can computers learn to solve problems without being explicitly programmed? In

function [y,tr]=beg(n)
%输入字符串长度，输出: y等式 和 tr字符串
s='+-/*';
y=s(ceil(rand*4));
tr(1)=y;
y=strcat('x',y);
y=strcat(y,'x');
for i=2:ceil(rand*n)
    tr(i)=s(ceil(rand*4));
    if tr(i)=='*'|| tr(i)=='/'
        y=strcat('(',y);
        y=strcat(y,')');
        y=strcat(y,tr(i));
        y=strcat(y,'x');
    else
        y=strcat(y,tr(i));
        y=strcat(y,'x');    
    end
end