Why is this code returning a blank plot?

Question

Lakerpurp24 2019-10-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/482944-why-is-this-code-returning-a-blank-plot

关闭： MATLAB Answer Bot 2021-8-20

v = 240
i = 4.17
z = v/i
 
pf = -1
 
for count = 1:1:20
    r = z * (pf)
    x = z * sin(acos(pf))
    voltage_reg(count) = ((i * ((r * cos(pf)) + (x * sin(pf))))/v) * 100
    pf = pf+.1
end
 
 
plot(pf,voltage_reg)

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

此问题已关闭。

Answer 1

Manuel Salmerón 2019-10-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/482944-why-is-this-code-returning-a-blank-plot#answer_394232

The variable pf is a scalar. Probably you wanted to store it into a vector instead.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Walter Roberson 2019-10-1

Right. At the point of the plot() call, pf is a scalar that stores the last value that was assigned due to the pf = pf+.1 statement. That is, you should note, a value that was never used for computation, because you increment it after you compute with it the last time.

I recommend that you read

https://www.mathworks.com/matlabcentral/answers/480004-need-help-with-taking-an-array-inside-a-for-loop-and-plotting-it#answer_391484