how do I find where a function is defined (equivalent of "which" command in bash)

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PeterB 2021-7-14

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编辑： PeterB 2021-7-14

When I start Matlab on one of my work machines, I get the message:

"Warning: Function count has the same name as a MATLAB builtin.."

I know exactly what the message means, but I do not know how to fix it, because I can not find where I have defined the function "count". If this was in a bash shell I would type the command "which count". Is there a Matlab equivalent, which shows me where the function "count" has been redefined?

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PeterB 2021-7-14

编辑：PeterB 2021-7-14

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Thanks everyone. I feel a bit silly not trying all permutations. I tried:

which(count)

but not

which count

or

which("count")

which both worked. I was just a bit disoriented not being at my normal desk and without my glasses!

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Answer 1

Cris LaPierre 2021-7-14

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编辑：Cris LaPierre 2021-7-14

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Yes, there is a which command in MATLAB. Note that count is an overloaded function, meaning it exists in several toolboxes. Here are the results in R2021a.

which -all count
built-in (/MATLAB/toolbox/matlab/strfun/count)
count is a built-in method                                % Shadowed string method
/MATLAB/toolbox/matlab/codetools/@mtree/count.m           % Shadowed mtree method
/MATLAB/toolbox/matlab/bigdata/@tall/count.m              % Shadowed tall method
/MATLAB/toolbox/parallel/parallel/@codistributed/count.m  % Shadowed codistributed method

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PeterB 2021-7-14

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OK, sorry for my silliness at not trying "which count" (see my comment under the question), now a follow-up question: does this mean a user will always see this message on startup, at least in our configuration? It just seems needlessly confusing when the user has not written any "count" function:

>> Warning: Function count has the same name as a MATLAB builtin. We suggest you
rename the function to avoid a potential name conflict. 
>> which -all count
built-in (C:\Program Files\MATLAB\R2020a\toolbox\matlab\strfun\count)
count is a built-in method                                                       % string method
C:\Program Files\MATLAB\R2020a\toolbox\matlab\codetools\@mtree\count.m           % mtree method
C:\Program Files\MATLAB\R2020a\toolbox\matlab\bigdata\@tall\count.m              % tall method
C:\Program Files\MATLAB\R2020a\toolbox\mbc\mbcdesign\@designdev\count.m          % designdev method
C:\Program Files\MATLAB\R2020a\toolbox\parallel\parallel\@codistributed\count.m  % codistributed method
C:\Program Files\MATLAB\R2020a\toolbox\local\count.m                             % Shadowed
>> 

Walter Roberson 2021-7-14

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Yes, the user will always see that message on startup.

C:\Program Files\MATLAB\R2020a\toolbox\local\count.m

What is the point of that? It is shadowed with the current path settings, so it will not be invoked -- the strfun\count version will be invoked for datatypes other than the ones listed as having @ .

If the intent is to have it be active only for a particular data type, you should build it into the class for that datatype.

PeterB 2021-7-14

编辑：PeterB 2021-7-14

I didn't create it so I don't know what the intention was. (It's not the computer I usually use.) But thank you: now I know why it is giving the warning, and why I am getting a warning for the "count" function and not for anything else.

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