Files
src_old/examples/H5Part/read_strided.c
T
gsell 542daf7fc2 C examples:
- define dummy MPI macros to be used in serial compilation, closing #10
- cleanup some "unused variable" warnings
- fix some format warnings, using C99 format macros
2017-06-23 15:37:46 +02:00

75 lines
2.4 KiB
C

/*
Copyright (c) 2006-2015, The Regents of the University of California,
through Lawrence Berkeley National Laboratory (subject to receipt of any
required approvals from the U.S. Dept. of Energy) and the Paul Scherrer
Institut (Switzerland). All rights reserved.
License: see file COPYING in top level of source distribution.
*/
#include "H5hut.h"
#include "examples.h"
#include <stdlib.h>
// name of input file
const char* fname = "example_strided.h5";
// H5hut verbosity level
const h5_int64_t h5_verbosity = H5_VERBOSE_DEFAULT;
//const h5_int64_t h5_verbosity = H5_DEBUG_ALL;
int
main (
int argc, char* argv[]
){
// initialize MPI & H5hut
MPI_Init (&argc, &argv);
MPI_Comm comm = MPI_COMM_WORLD;
int comm_size = 1;
MPI_Comm_size (comm, &comm_size);
int comm_rank = 0;
MPI_Comm_rank (comm, &comm_rank);
H5AbortOnError ();
H5SetVerbosityLevel (h5_verbosity);
// open file and go to first step
h5_file_t file = H5OpenFile (fname, H5_O_RDONLY, H5_PROP_DEFAULT);
H5SetStep (file, 0);
// compute number of particles this process has to read
h5_ssize_t num_particles_total = H5PartGetNumParticles (file);
h5_ssize_t num_particles = num_particles_total / comm_size;
if (comm_rank+1 == comm_size)
num_particles += num_particles_total % comm_size;
printf ("[proc %d]: particles in view: %lld\n", comm_rank, (long long)num_particles);
printf ("[proc %d]: total number of particles: %lld\n",
comm_rank, (long long unsigned)num_particles_total);
// set number of particles and memory stride
H5PartSetNumParticlesStrided (file, num_particles, 6);
// read data
h5_float64_t* data = calloc (6*num_particles, sizeof (*data));
H5PartReadDataFloat64 (file, "x", data+0);
H5PartReadDataFloat64 (file, "y", data+1);
H5PartReadDataFloat64 (file, "z", data+2);
H5PartReadDataFloat64 (file, "px", data+3);
H5PartReadDataFloat64 (file, "py", data+4);
H5PartReadDataFloat64 (file, "pz", data+5);
// print dataset "x"
for (int i = 0; i < num_particles*6; i+=6) {
printf ("[proc %d]: local index = %d, value = %6.3f\n",
comm_rank, i, data[i]);
}
// cleanup
free (data);
H5CloseFile (file);
MPI_Finalize ();
return 0;
}