How to I resolve "the operation or expression '(' has no effect" when plotting?

I am trying to plot two vectors, where QTH is a row vector of length 5. This is the command as it appears in my code:

You can see the first bracket is highlighted and underlined with the red squiggly error mark. When I hover over the error with my cursor I get the message:

the operation or expression '(' has no effect.

Does anyone have any idea why I would get this error for a simple plot?

Answer 1

[Sandeep Math]

Try:

figure
plot([1:5], QTL)

More info: http://www.mathworks.com/help/matlab/ref/specialcharacters.html

[Jayne]

I figured out that I had previously defined a variable called "plot" and this was the reason for this error message. It is important to pay attention to variable names in code, lesson learned. Thank you for your help.

[Walter Roberson]

The [] around the 1:5 is not needed.

Using a variable named plot() will usually cause problems.

Also watch out for spaces after names: it can lead to the parser thinking that you are using the "command" form instead of the "function" form.