From d3ae9cb57a78bca4098f2e970caa74108cbc6c7c Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@drexel.edu>
Date: Tue, 9 Nov 2010 11:23:38 -0500
Subject: [PATCH] Remove src/poisson_2d/P_2d.c (duplicated poisson_2d.c).

---
 src/poisson_2d/P_2d.c | 223 ------------------------------------------
 1 file changed, 223 deletions(-)
 delete mode 100644 src/poisson_2d/P_2d.c

diff --git a/src/poisson_2d/P_2d.c b/src/poisson_2d/P_2d.c
deleted file mode 100644
index e16928b..0000000
--- a/src/poisson_2d/P_2d.c
+++ /dev/null
@@ -1,223 +0,0 @@
-/*
-    Over-relaxation solution to Poisson equation
-
-    Syntax
-         Poisson  N  N_x  N_y
-            ( Max # iteration, grid in x, grid in y )
-
-    Note: only written for equal x and y meshes -- N_x = N_y
-
-    IBOUND:  positions on grid corresponding to boundaries
-
-    Modular code - simple main code - logical functions
-
-
-    Build & use of code
-
-gcc poisson_2d.c -lm -o  poisson_2d
-
-./poisson_2d  N  N_x  N_y | plot_image.py -s N_x,N_y -t "2d Poisson"
-
-*/
-
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <math.h>
-
-#define MAX_x 350                       /* maximum dimensions   */
-#define MAX_y 350
-
-#define EPS 1.0e-7                      /* tolerance in solution */
-
-#define IMAGE 1                         /* image - yes (1) - no (0) */
-
-                                        /* global array & file to record solution */
-int   ibound[MAX_x][MAX_y];
-double phi[MAX_x][MAX_y], ff[MAX_x][MAX_y];
-
-
-/* lattice definition & iteration number */
-void set_grid ( int argc, char *argv[], int *N_iterations, 
-                int *NI, int *NJ, double *h )
-{
-    if ( argc != 4 ) 
-      {
-        printf( " Syntax: poisson  N  N_x  N_y   ( where N_x = N_y ) \n" );
-        exit(1);
-      }
-    *N_iterations = atoi(argv[1]);
-    *NI = atoi(argv[2]);
-    *NJ = atoi(argv[3]);
-
-    if ( *NI != *NJ ) 
-      {
-        fprintf( stderr, " Code only setup for N_x = N_y \n");
-        exit(1);
-      }
-
-    if ( *NI > MAX_x || *NJ > MAX_y) 
-      {
-        fprintf( stderr, " Grid dimensions too large \n");
-        exit(1);
-      }
-
-    *h = 1.0/(double)(*NI-1);
-}
-
-
-/* initial phi values, source & boundary conditions */
-void initial_source_and_boundary ( int NI, int NJ )
-{
-    int i, j, i_s;
-    double r2;
-                                        /* initial fields & source*/
-    for ( i=0 ; i<NI ; i++ )
-      {
-        for ( j=0 ; j<NJ ; j++)
-	  {
-            r2 = (i-NI/5)*(i-NI/5) + (j-3*NJ/4)*(j-3*NJ/4);
-            ff[i][j] = 7000 * exp( - 0.01 * r2 );
-            ibound[i][j] = 0;
-            phi[i][j] = 0.0;
-	  } 
-      }
-                                        /* Boundary Conditions */
-    for ( j=0 ; j<NJ ; j++)
-      {
-        ibound[0][j] = 1;
-        phi[0][j] = 2.0;
-        ibound[NI-1][j] = 1;
-        phi[NI-1][j] = 2.0;
-      }
-    for ( i=0 ; i<NI ; i++ )
-      {
-        ibound[i][0] = 1;
-        phi[i][0] = 2.0;
-        ibound[i][NJ-1] = 1;
-        phi[i][NJ-1] = 2.0;
-      }
-                                        /* single values somewhere in square */
-    i_s = 4*NI/5;
-    ibound[i_s][3*NJ/4] = 1;
-    phi[i_s][3*NJ/4] = -25.0;
-    i_s = NI/3;
-    ibound[i_s][NJ/3] = 1;
-    phi[i_s][NJ/3] = -10.0;
-
-
-                                        /* echo input */
-    fprintf( stderr, " Grid size: %d x %d \n", NI, NJ );
-
-}
-
-
-/* check solution & output field data for image */
-void output_results( int NI, int NJ, double h )
-{
-    int    i, j;
-    double aux, phi_min, phi_max, residual, largest_residual;
-
-                                        /* check if solution is */
-                                        /* really a solution */
-    fprintf( stderr, " Check - ( LHS - RHS ) \n");
-    largest_residual = 0.0;
-    for ( i=0 ; i<NI ; i++ )
-      {
-      for ( j=0 ; j<NJ ; j++)
-        {
-                                        /* min & max of phi as an aside */
-          if ( phi[i][j] < phi_min ) phi_min = phi[i][j];
-          if ( phi[i][j] > phi_max ) phi_max = phi[i][j];
-
-          if ( ibound[i][j] == 0 )
-	    {
-            residual =  phi[i+1][j] + phi[i-1][j] + 
-                             phi[i][j+1] + phi[i][j-1] -
-                               4.0 * phi[i][j] - h * h * ff[i][j];
-	    }
-          else
-	    {
-            residual = 0.0;
-	    }
-          if( fabs( residual ) > largest_residual ) 
-                          largest_residual = fabs( residual );
-        }
-      }
-
-      fprintf( stderr, "largest residual : %e \n", largest_residual );
-
-                                        /* output phi for image */
-    if ( IMAGE == 1 )
-    {
-      aux = 255.0 / ( phi_max - phi_min );
-      for ( i=0 ; i<NI ; i++ )
-        {
-          for ( j=0 ; j<NJ ; j++)
-               printf( " %f \n", aux * ( phi[i][j] - phi_min ) );
-        }
-    } 
-}
-
-
-/* one Gauss-Siedel iteration */
-void Gauss_Siedel_step( int NI, int NJ, int iter, 
-           double *diff, double h )
-{
-      int    i, j;
-      double difference, aux, chi;
-
-                                        /* over-relaxation control */
-      chi = 1.0;
-      if ( iter > 30 ) chi = 1.2;
-      if ( iter > 50 ) chi = 1.8;
-	                                /* Gauss-Siedel update */
-      difference = 0.0;
-      for ( i=0 ; i<NI ; i++ )
-        {
-        for ( j=0 ; j<NJ ; j++)
-	  {
-          if ( ibound[i][j] == 0 )
-	    {
-              aux = phi[i][j];
-              phi[i][j] = 0.25 * ( phi[i+1][j] + phi[i-1][j] + 
-                             phi[i][j+1] +phi[i][j-1] - h * h * ff[i][j] );
-              phi[i][j] = (1-chi)*aux + chi*phi[i][j];
-              if ( difference <  fabs( aux - phi[i][j] ) )
-                  difference = fabs( aux - phi[i][j] );    
-	    }
-	  }
-        }
-      fprintf( stderr, " iter: %d - error %e \n", iter, difference );
-      *diff=difference;
-}
-
-
-
-
-int main ( int argc, char *argv[] )
-{
-    double h;
-    int    NI, NJ, i, j;
-    double diff, aux, chi;
-    int    N_iterations, iter;
-
-                                        /* lattice definition & */
-                                        /* iteration number */
-    set_grid ( argc, argv, &N_iterations, &NI, &NJ, &h );
-                                        /* initial fields, source */
-                                        /* & boundary conditions */
-    initial_source_and_boundary ( NI, NJ );
-                                        /* iterate the solution */
-    for ( iter=1 ; iter<N_iterations ; iter++ )
-      {
-	                                /* Gauss-Siedel iteration */
-        Gauss_Siedel_step( NI, NJ, iter, &diff, h );
-                                        /* solution accurate enough ? */
-        if ( diff < EPS ) break;
-      }
-                                        /* check & output the phi field */
-    output_results ( NI, NJ, h );
-
-}
-
-- 
2.26.2