.TH MPI_Wtime 3 "6/24/2006" "LAM/MPI 7.1.4" "LAM/MPI"
.SH NAME
MPI_Wtime \-  Returns an elapsed time on the calling processor 
.SH SYNOPSIS
.nf
#include <mpi.h>
double MPI_Wtime(void)
.fi
.SH RETURN VALUE

Time in seconds since an arbitrary time in the past.

.SH NOTES

This is intended to be a high-resolution, elapsed (or wall) clock.
See 
.I MPI_Wtick
to determine the resolution of 
.I MPI_Wime
\&.
If the
attribute 
.I MPI_WTIME_IS_GLOBAL
is defined and true, then the value is
synchronized across all processes in 
.I MPI_COMM_WORLD
\&.


.SH NOTES FOR FORTRAN

This function is declared as 
.I DOUBLE PRECISION MPI_WTIME()
in
Fortran.

.SH SEE ALSO
MPI_Wtick, MPI_Comm_get_attr
.br

.SH MORE INFORMATION

For more information, please see the official MPI Forum web site,
which contains the text of both the MPI-1 and MPI-2 standards.  These
documents contain detailed information about each MPI function (most
of which is not duplicated in these man pages).

.I http://www.mpi-forum.org/


.SH ACKNOWLEDGEMENTS

The LAM Team would like the thank the MPICH Team for the handy program
to generate man pages ("doctext" from
.I ftp://ftp.mcs.anl.gov/pub/sowing/sowing.tar.gz
), the initial
formatting, and some initial text for most of the MPI-1 man pages.
.SH LOCATION
wtime.c