Dispatching matrix size optimised

prod_mat_vec/main.c

@@ -3,7 +3,7 @@
 #include <mpi.h>
 #include <time.h>
 
-#define DEBUG 0
+#define DEBUG 1
 
 /*
 Commands :
@@ -11,25 +11,6 @@ cd 'B:\Mes Documents\progra\calcInt\'
 C:\MPICH2\bin\mpiexec.exe -localonly 10
 */
 
-/*
-*   The reference book says we should use all_gather and all_gatherv to make all the processors
-*   access the x vector.
-*   BUT, what fonction should we use to get the entire . Moreover
-*   the website http://mpitutorial.com say that MPI_Allgather should be used "only"
-*   if all the processes contains a part of the data and EACH ONE want the entire data
-*   dispatched through the processes.
-*   This image :http://mpitutorial.com/tutorials/mpi-scatter-gather-and-allgather/allgather.png
-*   Show this point.
-*   More over according to the problematic given MPI_Scatter and MPI_Gather seems to be
-*   more usable in this specific context of a dense matrix vector product.
-*
-*   Moreover, it is said that we should use allgatherv to get the final matrix but, if we consider
-*   this stackoverflow answer :
-*   http://stackoverflow.com/questions/15049190/difference-between-mpi-allgather-and-mpi-alltoall-functions#answer-34113431
-*   We see that using all gatherv will duplicate the data through each processor.
-*   Using gather seems more appropriated.
-*/
-
 void printMatrix(int width, int height, float **matrix){
     for(int i=0; i!=height; i++){
         for(int j=0; j!=width; j++){
@@ -104,10 +85,9 @@ int main (int argc, char *argv[]) {
         h_prob=size_prob/size; // h_prob is the processus' problem height
         h_base=h_prob;
     }else{
-        if(rank!=size-1)
-            h_prob=(size_prob/size)+1;
-        else{
-            h_prob=size_prob%h_base;
+        h_prob=(size_prob/size);
+        if(rank<size_prob%h_base-1){
+            h_prob+=1;
         }
     }
     w_prob=size_prob; // w_prob is not dependent of the number of processus.

prod_mat_vec/prod_mat_vec.depend

 # depslib dependency file v1.0
-1488910513 source:b:\mes documents\progra\calcint\prod_mat_vec\main.c
+1488995164 source:b:\mes documents\progra\calcint\prod_mat_vec\main.c
 	<stdio.h>
 	<stdlib.h>
 	<mpi.h>