MPIMin.c File Reference

Functions to compute the minimum over all MPI ranks. More...

#include <mpivars.h>

Go to the source code of this file.

Functions
int	MPIMin_integer (int *global, int *var, int size, void *comm)
int	MPIMin_double (double *global, double *var, int size, void *comm)

Detailed Description

Functions to compute the minimum over all MPI ranks.

Author

Debojyoti Ghosh

Definition in file MPIMin.c.

Function Documentation

MPIMin_integer()

int MPIMin_integer	(	int *	global,
		int *	var,
		int	size,
		void *	comm
	)

Compute the global minimum over all MPI ranks in a given communicator for int datatype.

• If var is an array of size greater than 1, global will be an array of the same size with each element as the minimum value of he that element in var on all the MPI ranks in the given communicator.

Parameters

global	array to contain the global minimums
var	the local array
size	size of the local array
comm	MPI communicator

Definition at line 15 of file MPIMin.c.

{
#ifdef serial
  int i;
  for (i = 0; i < size; i++)  global[i] = var[i];
#else
  MPI_Allreduce((var==global?MPI_IN_PLACE:var),global,size,MPI_INT,MPI_MIN,*((MPI_Comm*)comm));
#endif
  return(0);
}

MPIMin_double()

int MPIMin_double	(	double *	global,
		double *	var,
		int	size,
		void *	comm
	)

Compute the global minimum over all MPI ranks in a given communicator for double datatype.

• If var is an array of size greater than 1, global will be an array of the same size with each element as the minimum value of that element in var on all the MPI ranks in the given communicator.

Parameters

global	array to contain the global minimums
var	the local array
size	size of the local array
comm	MPI communicator

Definition at line 38 of file MPIMin.c.

{
#ifdef serial
  int i;
  for (i = 0; i < size; i++)  global[i] = var[i];
#else
  MPI_Allreduce((var==global?MPI_IN_PLACE:var),global,size,MPI_DOUBLE,MPI_MIN,*((MPI_Comm*)comm));
#endif
  return(0);
}