Added assertion to segfaulting function.

modsim/ass4_taddeus/vibstring/Makefile

 CC=mpicc
-CFLAGS=-Wall -Wextra -pedantic -std=c99 -O0 -D_GNU_SOURCE
+CFLAGS=-Wall -Wextra -pedantic -std=c99 -O0 -D_GNU_SOURCE -g
 LDFLAGS=-lm
 
 all: seq par

modsim/ass4_taddeus/vibstring/par.c

@@ -3,6 +3,7 @@
 #include <string.h>
 #include <math.h>
 #include <mpi.h>
+#include <assert.h>
 
 double **y = NULL, dx;
 int steps, time, start, rank, tasks;
@@ -21,6 +22,7 @@ static inline int last_node() {
  */
 void connect(int state) {
     double send[2], recv[2];
+    assert(tasks);
     int source = (rank - 1 + tasks) % tasks, target = (rank + 1) % tasks;
     MPI_Status status;
 
@@ -144,6 +146,13 @@ int main(int argc, char **argv) {
     void (*init_method)(double, double);
     double l, tau, constant;
 
+    // Parse arguments
+    if( argc < 7 ) {
+        printf("Usage: %s INIT_METHOD CALCULATION_STEPS LENGTH DX TAU N|XP\n",
+               argv[0]);
+        return EXIT_FAILURE;
+    }
+
     // Initialize and setup MPI
     if( (error = MPI_Init(&argc, &argv)) != MPI_SUCCESS ) {
         printf("MPI_init failed (error %d)\n", error);
@@ -154,13 +163,6 @@ int main(int argc, char **argv) {
     MPI_Comm_size(MPI_COMM_WORLD, &tasks);
     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
 
-    // Parse arguments
-    if( argc < 7 ) {
-        printf("Usage: %s INIT_METHOD CALCULATION_STEPS LENGTH DX TAU N|XP\n",
-               argv[0]);
-        return EXIT_FAILURE;
-    }
-
     if( !strcmp(argv[1], "sinus") ) {
         init_method = init_sinus;
     } else if( !strcmp(argv[1], "plucked") ) {

modsim/ass4_taddeus/vibstring/par.sh

-#!/bin/sh
+#!/bin/bash
 NUM_PROCESSES=${1-4} # Default: 4 processes
 #RSH_AGENT=rsh
 #MPI_HOSTFILE=~/.mpirun.machines
 PROGRAM_EXEC=par
-ARGS=sinus 1001 1 .01 1 1
+ARGS="sinus 1001 1 .01 1 1"
 
-mpirun -np $NUM_PROCESSES $PROGRAM_EXEC $@
+mpirun -np $NUM_PROCESSES $PROGRAM_EXEC $ARGS
 #mpirun -np $NUM_PROCESSES --mca pls_rsh_agent $RSH_AGENT \
 #    --hostfile $MPI_HOSTFILE $PROGRAM_EXEC