Matrix is singular to working precision.

Question

jack knipler 2016-4-13

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/278708-matrix-is-singular-to-working-precision

编辑： Walter Roberson 2016-4-13

采纳的回答： Roger Stafford

在 MATLAB Online 中打开

Hi

I entered some code to produce to 3d graphs side by side.

When running, the graphs are shown with one of them not having anything on them. "Matrix is singular to working precision." is shown in the command window. If anyone could help with this problem, this is my code.

Thanks

x = -10:0.5:10;
y = -10:0.5:10;
[xx,yy] = meshgrid(x,y);
subplot(1,2,1)
zz = xx.^2 - yy.^2;
mesh(xx,yy,zz);
subplot(1,2,2)
zz = (xx * yy)*(xx.^2 - yy.^2 / xx.^2 + yy.^2);
mesh(xx,yy,zz);

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Roger Stafford 2016-4-13

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/278708-matrix-is-singular-to-working-precision#answer_217660

编辑：Roger Stafford 2016-4-13

在 MATLAB Online 中打开

The matrix xx.^2 is indeed singular by its very nature, since its rows are all alike. When you write yy.^2 / xx.^2 you are asking for the inverse of xx.^2, and hence get the error message. I believe you meant to have a dot in the division rather than matrix division, and perhaps a dot in the multiplication:

zz = (xx .* yy) .* (xx.^2 - yy.^2 ./ xx.^2 + yy.^2);

or perhaps you meant this:

zz = (xx .* yy) .* (xx.^2 - yy.^2) ./ (xx.^2 + yy.^2);