Hi,
Thx for help.
> How about something like this?:
>
> GivePeriodOfAngle(n0,d):=
> block([ni:n0],
> for i thru 200 do if (ni:doubling_map(ni,d))=n0 then return(i));
Yes it really works, but what ( and why ) makes that your program works
and my do not ?
/* my gives i */
G1(n0,d):=block(
[ni:doubling_map(n0,d)],
for i:1 step 1 thru 200 unless (n0=ni) do ni:doubling_map(ni,d),
return(i)
);
>
> This returns 'done' if it doesn't terminate successfully.
If the function will be used inside another function it can be a problem
because done is not a numerical value ( if I'm not wrong ). But it can
be changed to
G(n0,d):=
block([ni:n0],
for i thru 200 do if (ni:doubling_map(ni,d))=n0 then
if (ni=n0)then return(i) else
return(0));
(:-|
Still gives done for :
G(1,31000000);
Adam
>
> -s
>
> block(
> [ni:doubling_map(n0,d)],
> for i:1 step 1 thru 200 unless (n0=ni) do ni:doubling_map(ni,d),
> i
> );
>
>
>
>
> On Wed, Nov 26, 2008 at 4:24 PM, Adam Majewski <adammaj1 at o2.pl> wrote:
>
> Hi,
>
> I want to make function which computes period.
> Period is an integer number which shows how many iterates of
> rational number ( = n/d ) under doubling_map is needed to get the same
> value.
> I made 2 functions :
> - first looks nice but not works ( it seems that maxima does not see
> index of for loop out of loop.
> - second function uses go-loop. It works, but ...
>
> Can it be done better ?
>
> Adam Majewski
>
>
> ======== code ==================
>
>
>
> doubling_map(n,d):=mod(2*n,d);
>
>
> /* first function does not work,
> gives i as an output */
> /* Give Period Of rational external Angle
> under doubling map */
> GivePeriodOfAngle(n0,d):=block(
> [ni:doubling_map(n0,d)],
> for i:1 step 1 thru 200 unless (n0=ni) do ni:doubling_map(ni,d),
> i
> );
>
>
> /* this second function works */
> GiveP(n0,d):=block(
> [ni:n0,i:0],
> block(
> loop,
> ni:doubling_map(ni,d),
> i:i+1,
> if i<100 and not (n0=ni) then go(loop)
> ),
> if (n0=ni)
> then i
> else 0
> );
>
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu <mailto:Maxima at math.utexas.edu>
> http://www.math.utexas.edu/mailman/listinfo/maxima
>
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima