Antonie is right. You only allocated memory for b on rank 0. To receive b on other ranks, you need to allocate memory on them as well. --Junchao Zhang On Wed, May 20, 2015 at 5:37 AM, Antoine Rougier <[email protected]> wrote:

Hello,

I think your issue comes from b.vect=NULL (according to the used constructor) which is not a checked value in T Vector<T>::get(int i). By the way Ncol is no initialized before using it in MPI_Bcast.

best regards,

Antoine Rougier

On 05/20/2015 11:55 AM, Umesh Shisode wrote:

...

Hello Junchao,

I initialize vector b, but even then it is not working for broadcasting. It gives same error. As the vector class is user defined and also I use dynamic memory allocation. This may be the reason for failing. If you know about it then please tell. I am here attaching the zip file which contains only the vector class and main file as well as error I am facing. Please have a look at it. Thanks for your time. I am waiting for your reply.

Regards,

Umesh Sharad Shisode, M.Tech in Modeling and Simulation(2013-15), Centre for Modeling and Simulation, University of Pune.

On Tue, May 19, 2015 at 10:57 PM, Junchao Zhang <[email protected]> wrote:

...

Your code "MPI_Bcast(&b(0), b.get_row(), MPI_DOUBLE, 1, MPI_COMM_WORLD)" is OK. You can find manual of MPI_Bcast at http://mpi.deino.net/mpi_functions/MPI_Bcast.html Don't forget to initialize the vector b, in other words, allocate memory for it, on ALL ranks.

--Junchao Zhang

On Tue, May 19, 2015 at 9:27 AM, Umesh Shisode <[email protected]> wrote:

...

Hi Junchao,

I sort out the problem for MPI_Send() and MPI_Recv(), as I requested in last mail. Now I have one more difficulty which is how can I broadcast class object using MPI_Bcast() function. In my case, class is Vector (you can check it at vect_fun.h header file). I want to broadcast it to all processes. I have used dynamic memory allocation in the code. Please help me to solved the issue. I am waiting for your reply. Thanks.

Regards,

Umesh Sharad Shisode, M.Tech in Modeling and Simulation(2013-15), Centre for Modeling and Simulation, University of Pune.

On Tue, May 19, 2015 at 7:51 AM, Umesh Shisode <[email protected]> wrote:

...

Sorry Junchao,

Thanks for your reply. But my problem is with MPICH only. My question is how to send part of class object (in my case matrix object) from one process to another process using MPI_Send and receive using MPI_Recv functions. I tried a lot of way but couldn't do it. I hope you will help me. Thanks in advance. I have write a function to get the pointer address for first parameter of MPI_Send() function. Waiting for your reply.

Regards,

Umesh Sharad Shisode, M.Tech in Modeling and Simulation(2013-15), Centre for Modeling and Simulation, University of Pune.

On Mon, May 18, 2015 at 7:31 PM, Junchao Zhang <[email protected]> wrote:

...

Could not reproduce it with the latest MPICH. If the problem is not specific to MPICH, you'd better move your question to other forums like stackoverflow.

$mpirun -n 2 ./test Matrix A :

1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4

Vector b before broadcast: 1.000000, 2.000000, 3.000000, 4.000000 Matrix A column : 4 after sending: lLim = 2 uLim = 4 for rank : 1 count = 8

Matrix A column : 0for rank = 1 after receive: lLim = 2 uLim = 4 for rank : 1 Ncol after broadcasting = 4

--Junchao Zhang

On Mon, May 18, 2015 at 6:33 AM, Umesh Shisode <[email protected]> wrote:

...

Hello Sir / Madam,

This is Umesh Sharad Shisode, pursuing Masters in Modeling and Simulation, at Centre for Modeling and Simulation, Pune University. I am in the final stage of my course. My Masters Thesis title is :

Development of Conjugate Gradient solver in OpenFOAM / CPP using MPI

I am now doing MPI part of my project and facing some problems with MPI functions syntax. I am trying to use CPP class object with MPI functions but it is giving some error. Which I don't understand.

Operating system : LINUX Programming Language : CPP

Commands I am using are :

> mpic++ main.cpp -o result > mpirun -np 2 result

Please help me to sort out this issue . I am attaching herewith zip file containing the code which I want to parallelize with the png file containing error. Waiting for your reply. Thanks in advance.

Regards,

Umesh Sharad Shisode, M.Tech in Modeling and Simulation(2013-15), Centre for Modeling and Simulation, University of Pune.

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