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5.3.8 timer

  1. the CPU time (i.e, user and system time) used for each command is printed if timer >0 , if this time is bigger than a (customizable) minimal time and if printlevel+1 >= voice (which is by default true on the SINGULAR top level, but not true while procedures are executed).

  2. yields the CPU time used since the start-up of SINGULAR in a (customizable) resolution.

The default setting of timer is 0, the default minimal time is 0.5 seconds, and the default timer resolution is 1 (i.e., the default unit of time is one second). The minimal time and timer resolution can be set using the command line options --min-time and --ticks-per-sec and can be checked using system("--min-time") and system("--ticks-per-sec").

How to use timer in order to measure the time for a sequence of commands, see example below.

Note for Windows95/98:
The value of the timer cannot be used (resp. trusted) when SINGULAR is run under Windows95/98 (this is due to the shortcomings of the Windows95/98 operating system). Use rtimer, instead.

  timer=1; // The time of each command is printed
  int t=timer; // initialize t by timer
  ring r=0,(x,y,z),dp;
  poly p=(x+2y+3z+4xy+5xz+6yz)^20;
  // timer as int_expression:
  t;  // yields the time in ticks-per-sec (default 1)
==> 0
      // since t was initialized by timer
  int tps=system("--ticks-per-sec");
  t div tps; // yields the time in seconds truncated to int
==> 0
  system("--ticks-per-sec",1000); // set timer resolution to ms
  t=timer; // initialize t by timer
  timer-t;  // time in ms
==> 30
See Command line options; printlevel; rtimer; system; voice.