Thread Subject: counting for loop operations

i am required to calculated the complexity of a program.

is there a way to count the number of "for loop" operations? or the amount of calculations carried out?

depending on the number of inputs, N, the loops operate for 1:N so i just want to compare the complexity as N increases

thanks
P

"P Sherry" <pistolpetesherry@nospam.hotmail.com> wrote in message <f8kejl$34r$1@fred.mathworks.com>...
> i am required to calculated the complexity of a program.
>
> is there a way to count the number of "for loop" operations? or the amount of calculations carried out?
>
> depending on the number of inputs, N, the loops operate for 1:N so i just want to compare the complexity as N increases
>
> thanks
> P

pardon me if i'm a bit out of date, but i don't think the number of iterations of a loop is part of the measure of complexity. it may relate to performance or other things. complexity is usually measured by things like 'how many for loops are there', 'how deeply nested are conditional statements', and stuff like that, not how many times the code gets executed.

> pardon me if i'm a bit out of date, but i don't think the number of iterations of a loop is part of the measure of complexity. it may relate to performance or other things. complexity is usually measured by things like 'how many for loops are there', 'how deeply nested are conditional statements', and stuff like that, not how many times the code gets executed.
>

i do agree but i want to draw a comparison between the number of iterations that take place and the N inputs.

any hints?

P

"P Sherry" <pistolpetesherry@nospam.hotmail.com> wrote in message <f8kgkk$5in$1@fred.mathworks.com>...
> > pardon me if i'm a bit out of date, but i don't think the number of iterations of a loop is part of the measure of complexity. it may relate to performance or other things. complexity is usually measured by things like 'how many for loops are there', 'how deeply nested are conditional statements', and stuff like that, not how many times the code gets executed.
> >
>
> i do agree but i want to draw a comparison between the number of iterations that take place and the N inputs.
>
> any hints?
>
> P

the number of iterations of a for loop that has a parameter like 1:N is just N. if it gets more complicated like 1:.1:N then you can do length(1:.1:N) to see how many there are. but somehow i don't think that is what you think you are looking for.

P Sherry:
<SNIP complex obfuscation...

> i am required to calculated the complexity of a program.
> depending on the number of inputs, N, the loops operate for 1:N so i just want to compare the complexity as N increases...

hmmmm (?), well, if you are looking for the <cyclomatic complexity>, aka <mc cabe complexity>, you could try

% mlint -m3 -cyc your_m_file;
% eg,
     mlint -m3 -cyc printdlg;

us

us:
<SNIP down to incomplete snippet...

> mlint -m3 -cyc printdlg;

note: the latest <mlint> versions (finally) return a structure and some...
therefore, if you need to save your output, you could do this

     fnam='printdlg.m';
     [s,ff]=mlint('-m3','-cyc',fnam);
     ff
     s
     {s.message}.'

us

In article <f8kevn$cgs$1@fred.mathworks.com>,
David <dave@bigcompany.com> wrote:

>pardon me if i'm a bit out of date, but i don't think the number of
>iterations of a loop is part of the measure of complexity. it may
>relate to performance or other things. complexity is usually measured
>by things like 'how many for loops are there', 'how deeply nested are
>conditional statements', and stuff like that, not how many times the
>code gets executed.

The OP is talking about "big-O" complexity, O(), the rate at which
the algorithm executes dependant upon the size of the data.

A for loop with constant bounds has O(c) (i.e., a constant)
for that subexpression, but a for loop 1:n where n is the
size of the input, has O(n) complexity, and for sufficiently large n
would operate more slowly than any particular O(c) expression,
even if that expression was hundreds of terms long.

--
Programming is what happens while you're busy making other plans.