matlab7咋不识别peaks函数呢

burger

??? Attempt to execute SCRIPT peaks as a function.

Error in ==> plot32 at 2
z=peaks(x,y);
%源程序如下：
[x,y]=meshgrid(-3:0.125:3);
z=peaks(x,y);
figure(1)
plot3(x,y,z),grid on
title('多峰函数的三角形曲线')