[Next] [Prev] [_____] [Left] [Up] [Index] [Root]
Timing
Timing
Cputime() : -> FldReElt
Return the CPU time (as a real number of default precision)
used since the beginning of a Magma session.
Cputime(t) : FldReElt -> FldReElt
Return the CPU time (as a real number of default precision)
used since time t (as a real number). Time starts at 0.0 at the beginning
of a Magma session.
time statement;
Execute the statement and print the time taken when the statement is
completed.
vtime flag: statement;
vtime flag, n: statement:
If the verbose flag flag (see the function SetVerbose)
has a level greater than or equal to n, execute the statement and print
the time taken when the statement is completed. If the flag has
level 0 (i.e. is not turned on), still execute the statement, but
do not print the timing. In the first form of this statement, where
a specific level is not given, n is taken to be 1.
This statement is useful in Magma code
found in packages
where one wants to print the timing of some sub-algorithm if and only if
an appropriate verbose flag is turned on.
Example State_Time (H1E17)
The time command can be used to time a single statement.
> n := 2^109-1;
> time Factorization(n);
[<745988807, 1>, <870035986098720987332873, 1>]
Time: 0.149
Alternatively, we can extract the current time t and use Cputime.
This method can be used to time the execution of several statements.
> m := 2^111-1;
> n := 2^113-1;
> t := Cputime();
> Factorization(m);
[<7, 1>, <223, 1>, <321679, 1>, <26295457, 1>, <319020217, 1>, <616318177, 1>]
> Factorization(n);
[<3391, 1>, <23279, 1>, <65993, 1>, <1868569, 1>, <1066818132868207, 1>]
> Cputime(t);
0.121
We illustrate a simple use of vtime with vprint within a function.
> function MyFunc(G)
> vprint User1: "Computing order...";
> vtime User1: o := #G;
> return o;
> end function;
> SetVerbose("User1", 0);
> MyFunc(Sym(4));
24
> SetVerbose("User1", 1);
> MyFunc(Sym(4));
Computing order...
Time: 0.000
24
[Next] [Prev] [_____] [Left] [Up] [Index] [Root]