print variable-name in Matlab
I have a function in Matlab that has some variables in it. I need to print out the variable_names (in case of an exception etc.). I am aware of inputname
function but it works for input_arguments only.
mat = [ 1 2 ; 3 4 ] ;
% disp(['Error in var: ' ??(a)])
% desired ouput: Error in var: mat (and NOT 1 2 ; 3 4!)
Thanks!
Solution 1:
varname=@(x) inputname(1);
disp(['Error in var: ' varname(mat)])
Solution 2:
Matlab essentially does not let you do that. However, you can write a helper function to ease your pain in creating output like that:
function disp_msg_var(msg, v)
disp([msg inputname(2)]);
end
which you could call like so in your case:
disp_msg_var('Error in: ', a);
You can read more discussion on the topic on the Mathworks forum
Additionally, to list all current variables with values you can use the who
function, but that is not the problem you presented.
Solution 3:
I'm adding another solution to the mix (one-liner):
function myFunction()
mat = [1 2; 3 4];
disp(['Error in var: ' feval(@(x)inputname(1),mat)])
end
Which outputs:
Error in var: mat
Solution 4:
If you want to print out the variables present in a function, you can use the function WHO. Here's an example using a simple function test.m
:
function test
a = 1;
b = 2;
varNames = who();
disp(sprintf('%s ','Variables are:',varNames{:}));
c = 3;
d = 4;
varNames = who();
disp(sprintf('%s ','Variables are:',varNames{:}));
end
Running this will give you the following output:
>> test
Variables are: a b
Variables are: a b c d varNames