Sometimes my 2-D plots won't show up.

Question

John 2022-10-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1815690-sometimes-my-2-d-plots-won-t-show-up

评论： John 2022-10-2

My 2-D plots will sometimes not plot. Sometimes they work, and sometimes they won't plot, and I can't figure out why. I'm very new to Matlab so it's probably something basic that i'm not doing correctly. The "New Figure option" in the Plots menu is checked.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Torsten 2022-10-2

在 MATLAB Online 中打开

Replace

y=K*(1+(Fb0*x/Na0))-realsqrt(((K*(1+Fb0*x/Na0))^2)-4*(K-1)*K*Fb0*x/Na0)/2*(K-1);

by

y=K*(1+(Fb0*x/Na0))-realsqrt(((K*(1+Fb0*x/Na0)).^2)-4*(K-1)*K*Fb0*x/Na0)/2*(K-1);

John 2022-10-2

Thank you so much! That worked! I appreciate explaining why it didn't work before. This is a great learning and great value!

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Star Strider 2022-10-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1815690-sometimes-my-2-d-plots-won-t-show-up#answer_1065055

在 MATLAB Online 中打开

Normally, that sort of problem is caused by using matrix division (/) instead of element-wise array division (./) however the ‘x’ vector does not appear in the denominator, so that is not the problem here. The only problem I found is that you need to use element-wise exponentiation (.^ instead of ^):

y=K*(1+(Fb0*x/Na0))-realsqrt(((K*(1+Fb0*x/Na0)).^2)-4*(K-1)*K*Fb0*x/Na0)/2*(K-1)

↑ ← HERE

however that should throw an error.

With that change, I don’t see any problems —

Fb0=0.5465;

Na0=1544;

K=8.33*10^-5;

x=0:36000:360000;

y=K*(1+(Fb0*x/Na0))-realsqrt(((K*(1+Fb0*x/Na0)).^2)-4*(K-1)*K*Fb0*x/Na0)/2*(K-1)

y = 1×11

0.0001 0.0337 0.0483 0.0597 0.0695 0.0783 0.0863 0.0938 0.1008 0.1075 0.1138

plot(x,y);