ModSim ass4 taddeus: Added 1 x-step for better drawing results.

modsim/ass4_taddeus/vibstring/par.c

@@ -5,6 +5,8 @@
 #include <mpi.h>
 #include <assert.h>
 
+#define VERBOSE
+
 double **y = NULL;
 int tasks, rank, steps, start;
 FILE *file;
@@ -64,8 +66,6 @@ void init_plucked(double l, double dx, double xp) {
     init_borders();
 }
 
-#define VERBOSE
-
 #ifdef VERBOSE
 #define PRINT_FORMAT "%e"
 
@@ -177,7 +177,7 @@ int main(int argc, char **argv) {
     file = fopen(filename, "w");
 
     // Calculate the indices of the string to calculate
-    total_steps = (int)ceil(l / dx);
+    total_steps = (int)ceil(l / dx) + 1;
     steps = total_steps / tasks;
     start = steps * rank;
 

modsim/ass4_taddeus/vibstring/par.sh

 #!/bin/bash
+if [ $# -lt 7 ]; then
+    echo "Usage: $0 NUM_PROCESSES INIT_METHOD TIME_STEPS LENGTH DX TAU N|XP"
+    exit 1
+fi
 mpirun -np ${1-4} ./par ${@:2:$#}
 #mpirun -np ${1-4} ./par sinus 100 1 .01 1 1
 #mpirun -np ${1-4} --mca pls_rsh_agent rsa \

modsim/ass4_taddeus/vibstring/report/report.tex

@@ -20,7 +20,7 @@
 
 \section{Inleiding}
 
-
+Het tweede deel van practicumopdracht 4 omhelst het programmeren van een
 
 \section{Theorie}
 

modsim/ass4_taddeus/vibstring/seq.c

@@ -3,6 +3,8 @@
 #include <string.h>
 #include <math.h>
 
+#define VERBOSE
+
 double **y = NULL, dx;
 int steps, time;
 
@@ -34,8 +36,6 @@ void init_plucked(double l, double xp) {
     y[2][steps - 1] = y[1][steps - 1] = y[0][steps - 1];
 }
 
-#define VERBOSE
-
 #ifdef VERBOSE
 #define PRINT_FORMAT "%e"
 
@@ -62,8 +62,8 @@ void calculate_steps(int time, double tau) {
     // position at t = 0 and the information that y(x, -dt) == y(x, dt)
     for( i = 1; i < steps - 1; i++ ) {
         x = i * dx;
-        y[1][i] = y[0][i] + .5 * tau * tau * (y[0][i-1] - 2 * y[0][i]
-                  + y[0][i+1]);
+        y[1][i] = y[0][i] + .5 * tau * tau * (y[0][i - 1] - 2 * y[0][i]
+                  + y[0][i + 1]);
     }
 
     #ifdef VERBOSE
@@ -86,7 +86,7 @@ void calculate_steps(int time, double tau) {
     for( t = 2; t < time; t++ ) {
         for( i = 1; i < steps - 1; i++ ) {
             y[next][i] = 2 * y[current][i] - y[prev][i] + tau * tau
-                * (y[current][i-1] - 2 * y[current][i] + y[current][i+1]);
+                * (y[current][i - 1] - 2 * y[current][i] + y[current][i + 1]);
         }
 
         #ifdef VERBOSE
@@ -126,14 +126,11 @@ int main(int argc, const char **argv) {
     tau = atof(argv[5]);
     constant = atof(argv[6]);
 
-    // Allocate a 3xN two-dimensional area that functions as a cyclic buffer
-    // for three states of the string (previous, current, next)
-    steps = (int)ceil(l / dx);
+    // Allocate a 3xN two-dimensional area that acts as a cyclic buffer for
+    // three states of the string (previous, current, next)
+    steps = (int)ceil(l / dx) + 1;
 
-    if( (y = (double **)malloc(3 * sizeof(double *))) == NULL ) {
-        puts("Error: could not allocate memory.");
-        exit(EXIT_FAILURE);
-    }
+    y = (double **)malloc(3 * sizeof(double *));
 
     for( i = 0; i < 3; i++ )
         y[i] = (double *)malloc(steps * sizeof(double));