# Invalid use of operator

17 views (last 30 days)
Xeven on 19 Dec 2022
Commented: Xeven on 19 Dec 2022
Completely new to coding...I put in this
\draw plot[domain=0:7, samples=200] (\x, {0.5*sin(deg(2*pi*\x))});. And Matlab says invalid use of operator what am I doing wrong, it might help if the program would highlight what it doesn't like...Thanks
##### 0 CommentsShow -2 older commentsHide -2 older comments

Sign in to comment.

### Accepted Answer

Fifteen12 on 19 Dec 2022
As Rik mentioned, this is not the correct language. MATLAB (like other programming environments/languages) has a strict syntax that you need to learn in order to use it.
I'm guessing at what you're trying to do, but a valid MATLAB command would be in the form of:
x = linspace(0, 7, 200);
y = 0.5 * sin(2*pi*x);
plot(x, y)
The error invalid use of operater came about because you were using the \ operator in a non-prescribed manner (in a way different than the way MATLAB defines the usage of the \ operator).
If you want to do more than just the simple plot command, then I would echo @Rik's advice to use the Onramp tutorial. It's slow going at first, but with great benefits once you learn it!
##### 1 CommentShow -1 older commentsHide -1 older comments
Xeven on 19 Dec 2022
Edited: Xeven on 19 Dec 2022
Cool I'll get back in the on ramp. I should have realized the language is different with different applications/programs. I had just opened the Open ai chat gpt app and entered draw a sine wave. It gave the code above. I didn't know where else to try it out except for Matlab. Thanks for the info and help.

Sign in to comment.

### More Answers (2)

Image Analyst on 19 Dec 2022
You need to specify MATLAB in your request to chatbot. Something like "Write a MATLAB program to draw a sine wave" and you should get something like this:
x = linspace(0, 7, 200);
period = pi/2;
y = 0.5 * sin(2 * pi * x / period);
plot(x, y, 'b-', 'LineWidth', 2)
fontSize = 20;
xlabel('x', 'FontSize', fontSize);
ylabel('y', 'FontSize', fontSize);
title('Sine Wave', 'FontSize', fontSize);
grid on;
##### 1 CommentShow -1 older commentsHide -1 older comments
Xeven on 19 Dec 2022
Awesome thanks for that info!!!(•‿•)

Sign in to comment.

Rik on 19 Dec 2022
Moved: Image Analyst on 19 Dec 2022
This is not Matlab code. What language is this?
If you have trouble with Matlab basics you may consider doing the Onramp tutorial (which is provided for free by Mathworks).
##### 1 CommentShow -1 older commentsHide -1 older comments
Xeven on 19 Dec 2022
Open ai chat gpt I forget all these codes aren't universal. Back to the onramp 🐢

Sign in to comment.

### Categories

Find more on Logical in Help Center and File Exchange

### Community Treasure Hunt

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

Start Hunting!