tridiagLUInit.c File Reference

Initialize the tridiagLU solver. More...

#include <stdio.h>
#include <string.h>
#include <tridiagLU.h>
#include <mpi.h>

Go to the source code of this file.

Functions
int	tridiagLUInit (void *r, void *c)

Detailed Description

Initialize the tridiagLU solver.

Author

Debojyoti Ghosh

Definition in file tridiagLUInit.c.

Function Documentation

tridiagLUInit()

int tridiagLUInit	(	void *	r,
		void *	c
	)

Initialize the tridiagLU solver by setting the various parameters in TridiagLU to their default values. If the file lusolver.inp is available, read it and set the parameters.

The file lusolver.inp must be in the following format:

    begin
        <keyword>   <value>
        <keyword>   <value>
        <keyword>   <value>
        ...
        <keyword>   <value>
    end

where the list of keywords are:

Keyword name	Type	Variable	Default value ---—
evaluate_norm	int	TridiagLU::evaluate_norm	1
maxiter	int	TridiagLU::maxiter	10
atol	double	TridiagLU::atol	1e-12
rtol	double	TridiagLU::rtol	1e-10
verbose	int	TridiagLU::verbose	0
reducedsolvetype	char[]	TridiagLU::reducedsolvetype	_TRIDIAG_JACOBI_

Parameters

r	Object of type TridiagLU
c	MPI communicator

Definition at line 39 of file tridiagLUInit.c.

{
  TridiagLU *t = (TridiagLU*) r;
  int       rank,ierr;
#ifdef serial
  rank  = 0;
#else
  MPI_Comm  *comm = (MPI_Comm*) c;
  if (!comm) rank = 0;
  else MPI_Comm_rank(*comm,&rank);
#endif

  /* default values */
  strcpy(t->reducedsolvetype,_TRIDIAG_JACOBI_);
  t->evaluate_norm = 1;
  t->maxiter       = 10;
  t->atol          = 1e-12;
  t->rtol          = 1e-10;
  t->verbose       = 0;

  /* read from file, if available */
  if (!rank) {
    FILE *in;
    in = fopen("lusolver.inp","r");
    if (!in) {
      printf("tridiagLUInit: File \"lusolver.inp\" not found. Using default values.\n");
    } else {
      char word[100];
      ierr = fscanf(in,"%s",word); if (ierr != 1) return(1);
      if (!strcmp(word, "begin")) {
          while (strcmp(word, "end")) {
              ierr = fscanf(in,"%s",word); if (ierr != 1) return(1);
                if      (!strcmp(word, "evaluate_norm"   )) ierr = fscanf(in,"%d" ,&t->evaluate_norm  );
                else if (!strcmp(word, "maxiter"         )) ierr = fscanf(in,"%d" ,&t->maxiter        );
            else if (!strcmp(word, "atol"            )) ierr = fscanf(in,"%lf",&t->atol           );
            else if (!strcmp(word, "rtol"            )) ierr = fscanf(in,"%lf",&t->rtol           );
              else if (!strcmp(word, "verbose"         ))   ierr = fscanf(in,"%d" ,&t->verbose        );
              else if (!strcmp(word, "reducedsolvetype"))   ierr = fscanf(in,"%s" ,t->reducedsolvetype);
          else if (strcmp(word,"end")) {
            char useless[100];
            ierr = fscanf(in,"%s",useless);
            printf("Warning: keyword %s in file \"lusolver.inp\" with value %s not recognized or extraneous. Ignoring.\n",word,useless);
          }
          if (ierr != 1) return(1);
        }
      } else {
          fprintf(stderr,"Error: Illegal format in file \"solver.inp\".\n");
        return(1);
      }
      fclose(in);
    }
  }

  /* broadcast to all processes */
#ifndef serial
  if (comm) {
    MPI_Bcast(t->reducedsolvetype,50,MPI_CHAR,0,*comm);
    MPI_Bcast(&t->evaluate_norm,1,MPI_INT,0,*comm);
    MPI_Bcast(&t->maxiter,1,MPI_INT,0,*comm);
    MPI_Bcast(&t->verbose,1,MPI_INT,0,*comm);
    MPI_Bcast(&t->atol,1,MPI_DOUBLE,0,*comm);
    MPI_Bcast(&t->rtol,1,MPI_DOUBLE,0,*comm);
  }
#endif

  return(0);
}