What is a child function?

When I 'Run and time' a function, and look at the bottom of the profile summary, it says "Self time is the time spent in a function excluding the time spent in its child functions. Self time also includes overhead resulting from the process of profiling. I can have a vague idea as to what it is based on context (i.e. subfunctions), but would like a more rigorous definition of what it is.

Answer 1

[Walter Roberson]

Child functions in this context is any routine that is called. For example,

   function test
     for K = 1 : 300000
       sort(rand(1,K));
     end

then "self-time" would be the total time spent executing test minus the time spent executing rand and sort

[Naveen]

So for example, the following code, when 'run and timed'

A = zeros(length(C) - end_info,n_mnr);

for i =start_row:length(C)
    A(i - end_info,:) = str2num(C{i});
end

produces this as one of the lines in the profile summary.

Function Name .......Calls ...... Total Time .......Self Time*

str2num............1048578 ....... 95.887s ........... 22.986s

What would be the child functions for str2num then? Does it refer to functions within the pre-programmed str2num?

[Walter Roberson]

Yes, str2num() calls several functions, with the major work being done by eval(), which is relatively inefficient.

Note: if you are concerned about performance you should look at str2double() or sscanf()