You did not write a nested function but a subfunction. yoyo2 is not nested inside test.

–Loren

function test(3)
 data = 1;
 yoyo2(3);
 data
end

function yoyo2(in)
 data = in;
end

Thanks,
Jung.

Thanks for your concerns. FYI, you can guarantee, in a nested function, that variables are local if you list them in the input or output argument list.

–Loren

Just a suggestion.

However, I was hoping to find something like the codemetrics that would summarize the nesting relationship. I couldn’t find anything on the file exchange, so I ended up doing it by hand & making a table in an Excel spreadsheet.

See if this helps. Put a break point in one of the nested functions, perhaps at the last executable statement. Type “who” at the MATLAB prompt. The display should show you local variables and up-level ones. If this helps, you can then do that for each of the nested functions. Tedious, yes, but I think it will get you the info you are looking for.

–Loren

I just wish there was some simple way to list all the variables a nested function could see. That would make de-bugging much easier.

function test1
x=ones(10000,10000);
tic
for i=1:100
x = tsqr(x);
end
toc

end

function a = tsqr(x)
a=(x+1)./x;
end

vs.

function test2
x=ones(10000,10000);
tic
for i=1:100
tsqr;
end
toc

    function  tsqr
        x =(x+1)./x;
    end

end

the first is slower(try with 1000) and gives out of memory error (with 10000)!

It just shows that, in some cases, there might be some important speed differences between a function and the same one nested, or using global variables.

Nested functions can be slower in some cases currently. We know we have some opportunities to optimize more. However, be very careful as it depends on how many variables, how much data there is, how much data changes, etc. I don’t think one experiment characterizes the larger picture fully.

–Loren