How to plot simple function

8 次查看（过去 30 天）
Ryan Ferrell
Ryan Ferrell 2020-4-23
评论： James Tursa 2020-4-23
I am trying to plot f(x)= 1/(1+25x^2) but am getting the error: File: drafts.m Line: 2 Column: 18
Invalid expression. When calling a function or indexing a variable,
use parentheses. Otherwise, check for mismatched delimiters.
x=linspace(-1,1,11);
y=(1/(1+(25*x^2));
plot(x,y)
if i change line 2 to y=sin(x) this works so why does this not work in this instance?

请先登录，再回答此问题。

回答（1 个）

James Tursa
James Tursa 2020-4-23
编辑：James Tursa 2020-4-23
Error message says to check for mismatched delimiters. So this
y=(1/(1+(25*x^2));
should be this with one fewer paren:
y=1./(1+(25*x.^2));
The / and ^ were changed to the element-wise operators ./ and .^ so that your function is "vectorized" and will work with arrays.
  2 个评论
Ryan Ferrell
Ryan Ferrell 2020-4-23
i understand why there needs the be an x. I forgot to write that in the question but why does "1" need to be "1."?
James Tursa
James Tursa 2020-4-23
I am not changing x to x. and 1 to 1.
I am changing / to ./ and ^ to .^
That is, the dots get attached to the operators / and ^, not to the operands 1 and x
The element-wise operators ./ and .^ are DIFFERENT operators from the matrix operators / and ^

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Annotations 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by