ModSim ass4 taddeus: Worked on vibrating string MPI part.

modsim/ass4_taddeus/vibstring/.gitignore

 seq
 par
+out*.txt

modsim/ass4_taddeus/vibstring/combine.py

+from sys import argv, exit
+
+def combine(numfiles):
+    files = range(int(numfiles))
+    lines = [open('out%d.txt' % i).readlines() for i in files]
+    return [' '.join([lines[j][i][:-1] for j in files]) for i in
+            range(len(lines[0]))]
+
+if __name__ == '__main__':
+    if len(argv) < 2:
+        print 'Usage: python %s TASKS' % argv[0]
+        exit()
+
+    print '\n'.join(combine(argv[1]))

modsim/ass4_taddeus/vibstring/draw.py

 #!/usr/bin/env python
-from sys import stdin
+from sys import stdin, argv, exit
 from pylab import figure, plot, axis, draw, ion, clf
 from time import sleep
-from sys import argv, exit
+from combine import combine
 
-if len(argv) < 2:
-    print 'Usage: python %s TIME_STEP [ DELAY ]' % argv[0]
+if len(argv) < 3:
+    print 'Usage: python %s TASKS TIME_STEP [ DELAY ]' % argv[0]
     exit()
 
-stride = int(argv[1])
-delay = .1 if len(argv) < 3 else float(argv[2])
+# tasks = 0 means sequential, above means parallel and having to combine the
+# different output files
+lines = combine(int(argv[1])) if int(argv[1]) else stdin.readlines()
+
+stride = int(argv[2])
+delay = .1 if len(argv) < 4 else float(argv[3])
 
 # Collect data
 y = []
-lines = stdin.readlines()
 x = map(float, lines[0].split(' '))
 for line in lines[1::stride]:
     y += [map(float, line.split(' '))]
@@ -30,4 +33,4 @@ for i in range(len(y)):
     plot(x, y[i], '-')
     axis(ranges)
     draw()
-    sleep(delay)
+    i and sleep(delay)

modsim/ass4_taddeus/vibstring/par.c

@@ -4,51 +4,50 @@
 #include <math.h>
 #include <mpi.h>
 
-double **y = NULL, dx;
-int steps, time, start, rank, tasks;
-
-static inline int first_node() {
-    return !rank;
-}
-
-static inline int last_node() {
-    return rank == tasks - 1;
-}
+double **y = NULL;
+int tasks, rank, steps, start;
+FILE *file;
 
 /*
  * Connect the string at both ends by sending the calculated border values and
  * receiving the outer borders calculated by the adjacent nodes
  */
-void connect(int state) {
-    double send[2], recv[2];
-    int source = (rank - 1 + tasks) % tasks, target = (rank + 1) % tasks;
+void interact(int state) {
+    int prev = (rank - 1 + tasks) % tasks, next = (rank + 1) % tasks;
     MPI_Status status;
 
-    send[0] = y[state][1];
-    send[1] = y[state][steps];
-
-    MPI_Sendrecv(send, 2, MPI_DOUBLE, target, MPI_ANY_TAG, recv, 2, MPI_DOUBLE,
-            source, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
+    // Left border
+    if( rank ) {
+        MPI_Sendrecv(&y[state][1], 1, MPI_DOUBLE, prev, 0, &y[state][0], 1,
+                MPI_DOUBLE, prev, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
+    }
 
-    y[state][0] = recv[0];
-    y[state][steps + 1] = recv[1];
+    // Right border
+    if( rank < tasks - 1 ) {
+        MPI_Sendrecv(&y[state][steps], 1, MPI_DOUBLE, next, 0,
+                &y[state][steps + 1], 1, MPI_DOUBLE, next, MPI_ANY_TAG,
+                MPI_COMM_WORLD, &status);
+    }
 }
 
-static inline void init_borders() {
+void init_borders() {
     // The string is attached at both ends
-    if( first_node() )
+    if( !rank )
         y[2][1] = y[1][1] = y[0][1];
-    else if( last_node() )
+    else if( rank == tasks - 1 )
         y[2][steps] = y[1][steps] = y[0][steps];
 
-    connect(0);
+    //interact(0);
 }
 
 /*
  * Fill the assigned string section with a sinus shape
  */
-void init_sinus(double l, double n) {
-    for( int i = 0; i < steps; i++ )
+void init_sinus(double l, double dx, double n) {
+    int i;
+    printf("start: %d\n", start);
+
+    for( i = 0; i < steps; i++ )
         y[0][i + 1] = sin(n * M_PI * (i + start) * dx / l);
 
     init_borders();
@@ -57,10 +56,11 @@ void init_sinus(double l, double n) {
 /*
  * Fill the assigned string section with a plucked shape
  */
-void init_plucked(double l, double xp) {
+void init_plucked(double l, double dx, double xp) {
     double x;
+    int i;
 
-    for( int i = 0; i < steps; i++ ) {
+    for( i = 0; i < steps; i++ ) {
         x = (i + start) * dx;
         y[0][i + 1] = x < xp ? x / xp : (l - x) / (l - xp);
     }
@@ -75,23 +75,20 @@ void init_plucked(double l, double xp) {
 
 void print(int index) {
     for( int i = 0; i < steps; i++ ) {
-        if( i || rank )
-            printf(" ");
+        if( i )
+            fprintf(file, " ");
 
-        printf(PRINT_FORMAT, y[index][i]);
+        fprintf(file, PRINT_FORMAT, y[index][i]);
     }
 
-    if( last_node() )
-        puts("");
-
-    fflush(stdout);
+    fprintf(file, "\n");
 }
 #endif
 
 /*
  *
  */
-void calculate_steps(int time, double tau) {
+void calculate_steps(int time, double dx, double tau) {
     double x;
     int i, t, prev = 0, current = 1, next = 2;
 
@@ -107,13 +104,12 @@ void calculate_steps(int time, double tau) {
     // Print x values (which are the same for every y-series)
     for( i = 0; i < steps; i++ ) {
         if( i )
-            printf(" ");
+            fprintf(file, " ");
 
-        printf(PRINT_FORMAT, (i + start) * dx);
+        fprintf(file, PRINT_FORMAT, (i + start) * dx);
     }
 
-    puts("");
-    fflush(stdout);
+    fprintf(file, "\n");
 
     // Print init states
     print(prev);
@@ -135,28 +131,19 @@ void calculate_steps(int time, double tau) {
         current = next;
         next = (next + 1) % 3;
 
-        connect(next);
+        interact(next);
     }
 }
 
 int main(int argc, char **argv) {
     int error, time, i, total_steps;
-    void (*init_method)(double, double);
-    double l, tau, constant;
-
-    // Initialize and setup MPI
-    if( (error = MPI_Init(&argc, &argv)) != MPI_SUCCESS ) {
-        printf("MPI_init failed (error %d)\n", error);
-        MPI_Abort(MPI_COMM_WORLD, error);
-        return EXIT_FAILURE;
-    }
-
-    MPI_Comm_size(MPI_COMM_WORLD, &tasks);
-    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+    void (*init_method)(double, double, double);
+    double l, tau, constant, dx;
+    char filename[9];
 
     // Parse arguments
     if( argc < 7 ) {
-        printf("Usage: %s INIT_METHOD CALCULATION_STEPS LENGTH DX TAU N|XP\n",
+        printf("Usage: %s INIT_METHOD TIME_STEPS LENGTH DX TAU N|XP\n",
                argv[0]);
         return EXIT_FAILURE;
     }
@@ -176,6 +163,20 @@ int main(int argc, char **argv) {
     tau = atof(argv[5]);
     constant = atof(argv[6]);
 
+    // Initialize and setup MPI
+    if( (error = MPI_Init(&argc, &argv)) != MPI_SUCCESS ) {
+        printf("MPI_Init failed (error %d)\n", error);
+        MPI_Abort(MPI_COMM_WORLD, error);
+        return EXIT_FAILURE;
+    }
+
+    MPI_Comm_size(MPI_COMM_WORLD, &tasks);
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+    // Open file for output
+    sprintf(filename, "out%d.txt", rank);
+    file = fopen(filename, "w");
+
     // Calculate the indices of the string to calculate
     total_steps = (int)ceil(l / dx);
     steps = total_steps / tasks;
@@ -195,19 +196,18 @@ int main(int argc, char **argv) {
     for( i = 0; i < 3; i++ )
         y[i] = (double *)malloc((steps + 2) * sizeof(double));
 
-    // Initialize the string values (sinus/plucked)
-    (*init_method)(l, constant);
-
-    // Calculate the specified number of steps
-    calculate_steps(time, tau);
+    // Initialize the string values (sinus/plucked) and calculate the specified
+    // number of steps
+    (*init_method)(l, dx, constant);
+    calculate_steps(time, dx, tau);
 
-    // Free allocated memory
+    // Cleanup
     for( i = 0; i < 3; i++ )
         free(y[i]);
 
     free(y);
 
-    // Finalize MPI
+    fclose(file);
     MPI_Finalize();
 
     return EXIT_SUCCESS;

modsim/ass4_taddeus/vibstring/par.sh

 #!/bin/sh
 NUM_PROCESSES=${1-4} # Default: 4 processes
-#RSH_AGENT=rsh
-#MPI_HOSTFILE=~/.mpirun.machines
-PROGRAM_EXEC=par
+RSH_AGENT=rsh
+MPI_HOSTFILE=~/.mpirun.machines
+PROGRAM_EXEC=./par
 ARGS=sinus 1001 1 .01 1 1
 
-mpirun -np $NUM_PROCESSES $PROGRAM_EXEC $@
+#mpirun -np $NUM_PROCESSES ./par sinus 100 1 .01 1 1
+mpirun -np $NUM_PROCESSES ./par sinus 3 1 .01 1 1
+#mpirun -np $NUM_PROCESSES $PROGRAM_EXEC $ARGS
 #mpirun -np $NUM_PROCESSES --mca pls_rsh_agent $RSH_AGENT \
 #    --hostfile $MPI_HOSTFILE $PROGRAM_EXEC