有人熟悉 Octave 么？问一个初学者的问题

JerryZhou

我只想在Octave 上用 mesh() 画出一个椭圆的上半部分，不知道为什么就提示我出错？

[PHP]
x = [-20:20]
[XX, YY] = meshgrid(x, x)
mesh(x, x, sqrt(5 - XX .^ 2 + YY .^ 2))
[/PHP]

错误信息：
error: for now, I can only save real matrices in 3D format
error: evaluating if command near line 59, column 7
error: evaluating if command near line 56, column 5
error: evaluating if command near line 41, column 3
error: called from `mesh' in file `/usr/share/octave/2.1.72/m/plot/mesh.m'