Error using save variable '...'not found

Why does it keep saying "Error using save variable '...'not found?"

[KALYAN ACHARJYA]

Pls share code?

[Walter Roberson]

When group is empty, then FullCWP_normPSD is not assigned to and so you would not be able to save it.

[Stephen23]

Do NOT use command syntax.

Always use function syntax.

https://www.mathworks.com/help/matlab/matlab_prog/command-vs-function-syntax.html

Answer 1

[Walter Roberson]

If you use the syntax

save FILENAME VARIABLENAME

or

save('FILENAME', 'VARIABLENAME')

then if no variable named VARIABLENAME exists in scope, you would get that error message.

For example that could happen if you think you are always computing something and so try to save it, but it turns out that there are cases where the value is not actually computed.

if V
    result = 1
elseif ~V
    result = 2;
end
save Output.mat result

This will not assign anything to result in some cases where V is a vector or array or is empty.