Possible matlab bug with text() function?

I'm having issues with the text function. I am copying your example from the documentation, and I get the following error:

"Subscript indices must either be real positive integers or logicals."

Here is the example:

x = 0:pi/20:2*pi;
y = sin(x);
plot(x,y)
text(pi,0,'\leftarrow sin(\pi)')

I am using Matlab 2013a. Very simple example, not sure why I can't replicate the documentation example. Thank in advance!

[Kevin Phung]

where is it throwing the error? It runs for me

[Azhar Ali]

Error is thrown for text function despite no other variables in workspace. Reboot of computer and Matlab resolved issue.

Answer 1

[madhan ravi]

When you name variable as the same name as the function this happens.

clear text plot sin % not sure which function you’re shadowing , but it definitely is a reason

Answer 2

[Azhar Ali]

I had no variables in my workplace (clear; clc; close all) and I still had the error. I rebooted computer and Matlab and it resolved the issue. Weird. Still don't know why I got the error, but problem is fixed. Thanks all.

[Steven Lord]

If this recurs, set an error breakpoint and run your code. When you receive the error, check if you are in a function named text.m (which would be shadowing the built-in text function.) If you are not, post the full text of the error message (all the text displayed in red, not just the "Subscript indices must either be real positive integers or logicals." part) and it may provide the information needed to determine the cause.

Answer 3

[Lola Gadea]

I have the same problem with the 2023a version:

x = 0:pi/20:2*pi;

y = sin(x);

plot(x,y)

text(pi,0,'\leftarrow sin(\pi)')

Index in position 1 is invalid. Array indices must be positive integers or logical values.

Error in example_labels5 (line 4)

text(pi,0,'\leftarrow sin(\pi)')

[Steven Lord]

What does this command show?

which -all text

built-in (/MATLAB/toolbox/matlab/graphics/primitive/text)

I'm betting it will show something that looks like the following instead of the text above (note the first line.)

text = 42;
which -all text

text is a variable.
built-in (/MATLAB/toolbox/matlab/graphics/primitive/text)  % Shadowed