diff --git a/exercice_bcast_Nicolas_FLEY/execution.png b/exercice_bcast_Nicolas_FLEY/execution.png
deleted file mode 100644
index 8deec2296c65f13dad1a6a8357f9278648296117..0000000000000000000000000000000000000000
Binary files a/exercice_bcast_Nicolas_FLEY/execution.png and /dev/null differ
diff --git a/exercice_bcast_Nicolas_FLEY/mpi_bcast.c b/exercice_bcast_Nicolas_FLEY/mpi_bcast.c
deleted file mode 100644
index da46f20a0ef8b6916074a65df903c3036daf5e31..0000000000000000000000000000000000000000
--- a/exercice_bcast_Nicolas_FLEY/mpi_bcast.c
+++ /dev/null
@@ -1,35 +0,0 @@
-#include <stdio.h>
-#include <mpi.h>
-
-/*
-Commands :
-cd 'B:\Mes Documents\progra\calcInt\'
-C:\MPICH2\bin\mpiexec.exe -localonly 10
-*/
-
-int main (int argc, char *argv[]) {
- int rank, size;
- MPI_Status status;
-
- int test=0;
- int message_to_send=7;
-
- MPI_Init (&argc, &argv); /* starts MPI */
-
- if(argc==2){
- message_to_send = atoi(argv[1]);
- }
-
- MPI_Comm_rank(MPI_COMM_WORLD, &rank); /* get current process id */
- MPI_Comm_size(MPI_COMM_WORLD, &size); /* get number of processes */
-
- if(rank==0){
- for(int i=1;i!=size;i++)
- MPI_Send(&message_to_send,1,MPI_INT,i,10,MPI_COMM_WORLD);
- }else{
- MPI_Recv(&message_to_send,1,MPI_INT,0,10,MPI_COMM_WORLD,&status);
- printf("%d received by %d\n",message_to_send,rank);
- }
-
- MPI_Finalize();
-}
diff --git a/exercice_bcast_Nicolas_FLEY/mpi_bcast_log.c b/exercice_bcast_Nicolas_FLEY/mpi_bcast_log.c
deleted file mode 100644
index d08a2d1cf05af6e5765ece042ef95374e4f4a83a..0000000000000000000000000000000000000000
--- a/exercice_bcast_Nicolas_FLEY/mpi_bcast_log.c
+++ /dev/null
@@ -1,77 +0,0 @@
-#include <stdio.h>
-#include <mpi.h>
-#include <math.h>
-
-/*
-Commands :
-cd 'B:\Mes Documents\progra\calcInt\'
-C:\MPICH2\bin\mpiexec.exe -localonly 10
-*/
-
-// explications given at the bottom of this file
-int whoSendNext(int loop,int rank); // to know who to send next
-int whoSendBef(int rank); // to know who send the message to the process
-
-int main (int argc, char *argv[]) {
- int rank, size, next, numLoopRecv;
- MPI_Status status;
-
- int test=0;
- int message_to_send=7;
- int numLoop=1;
-
- MPI_Init (&argc, &argv); /* starts MPI */
-
- if(argc==2){
- message_to_send = atoi(argv[1]);
- }
-/*
- for(int i=1;i!=10;i++){
- numLoopRecv=((int)(log2((double)i)+2.01));
- printf("###\n numLoopRecv : %d\n",numLoopRecv);
- printf("\nrank %d wait for %d\n",i,whoSendBef(numLoopRecv,i));
- printf("\nrank %d send for %d\n",i,whoSendNext(numLoopRecv,i));
- }
- return 0;
-*/
- MPI_Comm_rank(MPI_COMM_WORLD, &rank); /* get current process id */
- MPI_Comm_size(MPI_COMM_WORLD, &size); /* get number of processes */
-
- int numMaxLoop=((int)log2((double)size)+2.01); // get the rank of the final loop
-
- if(!(rank==0 && numLoop==1)){
- numLoop=((int)(log2((double)rank)+2.01)); // get the rank of the loop it will be when the process will receive the message
- printf("%d wait for reception from %d\n",rank,whoSendBef(numLoopRecv,rank));
- MPI_Recv(&message_to_send,1,MPI_INT,whoSendBef(numLoop,rank),10,MPI_COMM_WORLD,&status);
- }
- while(numLoop<=numMaxLoop){
- next=whoSendNext(numLoop,rank);
- if(next<size){ // will stop broadcast when all process have been reached
- printf("%d wait for a sending to %d\n",rank,next);
- MPI_Send(&message_to_send,1,MPI_INT,whoSendNext(numLoop,rank),10,MPI_COMM_WORLD);
- }
- numLoop+=1;
- }
- MPI_Finalize();
-}
-
-/*
-* Logic used is :
-* (turn : 1 2 3 4)
-* 0 will send to 1 then 2 then 4 then 8
-* 1 will send to 3 then 5 then 9
-* 2 will send to 6 then 10
-* 3 will send to 7 then 11
-* ...
-* n will send to ... n+2^(turn-1) then n+2^(turn) ...
-*/
-
-
-int whoSendNext(int loop,int rank){ // OK
- int inc=((int)(pow(2.0,((double)loop)-1.0)+0.01));
- return rank+inc;
-}
-int whoSendBef(int loop,int rank){
- int inc=((int)(pow(2.0,((int)log2((double)rank)+0.01))+0.01));
- return rank-inc;
-}
diff --git a/prod_mat_vec/main.c b/prod_mat_vec/main.c
new file mode 100644
index 0000000000000000000000000000000000000000..e8fd89df701968c88e0d284c69ed3b99ed9e6fd9
--- /dev/null
+++ b/prod_mat_vec/main.c
@@ -0,0 +1,43 @@
+#include <stdio.h>
+#include <mpi.h>
+
+/*
+Commands :
+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 processor
+* access the x vector. BUT, x isn't going to be modified in the process. 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, more than duplicate the data through each processor.
+* Using gather seems more appropriated.
+*/
+
+int main (int argc, char *argv[]) {
+ int rank, size;
+ MPI_Status status;
+
+ int test=0;
+
+ MPI_Init (&argc, &argv); /* starts MPI */
+
+ MPI_Comm_rank(MPI_COMM_WORLD, &rank); /* get current process id */
+ MPI_Comm_size(MPI_COMM_WORLD, &size); /* get number of processes */
+
+ MPI_Send(&test,1,MPI_DOUBLE,0,10,MPI_COMM_WORLD);
+ MPI_Recv(&test,1,MPI_DOUBLE,0,10,MPI_COMM_WORLD,&status);
+
+ MPI_Finalize();
+}
diff --git a/prod_mat_vec/prod_mat_vec.cbp b/prod_mat_vec/prod_mat_vec.cbp
new file mode 100644
index 0000000000000000000000000000000000000000..685b6583da3e7631a468db11516b8b04b1d5ad26
--- /dev/null
+++ b/prod_mat_vec/prod_mat_vec.cbp
@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
+<CodeBlocks_project_file>
+ <FileVersion major="1" minor="6" />
+ <Project>
+ <Option title="prod_mat_vec" />
+ <Option pch_mode="2" />
+ <Option compiler="gcc" />
+ <Build>
+ <Target title="Debug">
+ <Option output="bin/Debug/prod_mat_vec" prefix_auto="1" extension_auto="1" />
+ <Option object_output="obj/Debug/" />
+ <Option type="1" />
+ <Option compiler="gcc" />
+ <Compiler>
+ <Add option="-g" />
+ </Compiler>
+ </Target>
+ <Target title="Release">
+ <Option output="bin/Release/prod_mat_vec" prefix_auto="1" extension_auto="1" />
+ <Option object_output="obj/Release/" />
+ <Option type="1" />
+ <Option compiler="gcc" />
+ <Compiler>
+ <Add option="-O2" />
+ </Compiler>
+ <Linker>
+ <Add option="-s" />
+ </Linker>
+ </Target>
+ </Build>
+ <Compiler>
+ <Add option="-Wall" />
+ </Compiler>
+ <Unit filename="main.c">
+ <Option compilerVar="CC" />
+ </Unit>
+ <Extensions>
+ <code_completion />
+ <envvars />
+ <debugger />
+ </Extensions>
+ </Project>
+</CodeBlocks_project_file>