tree_stringrc.m

来自「本程序是基于matlab的时间序列预测模型GP源程序」· M 代码 · 共 21 行

function s = tree_stringrc(tree,ix,symbols)

operator = {'+','-','.*','.^'};
ss = '';
if tree.nodetyp(ix)==1 & ix*2+1<=tree.maxsize,
  sleft = tree_stringrc(tree,ix*2,symbols);      % 左子树
  sright = tree_stringrc(tree,ix*2+1,symbols);   % 右子树
  
  i = mod(ceil(abs(rand)*100),4)+1;
  ss = operator{i}; 
  
  s = strcat('(',sleft,')',ss,symbols{tree.nodetyp(ix)}{tree.node(ix)}, ...
     '(',sright,')');
else
    if tree.nodetyp(ix)==2,
      s = symbols{tree.nodetyp(ix)}{tree.node(ix)};
    else
        s='x';
    end
end
return