# MPI\_Bcast

Broadcasts a message from the process with rank "root" to all other processes of the communicator

## 📝 Syntax

* A = MPI\_Bcast(A, Root)
* A = MPI\_Bcast(A, Root, Comm)

## 📥 Input argument

* A - a nelson variable.
* Root - a integer value: rank of broadcast root.
* Comm - a MPI\_Comm object.

## 📤 Output argument

* A - broadcasted array.

## 📄 Description

This function is used to broadcast an array to all group members.

## 💡 Example

mpiexec(\[modulepath('mpi'), '/examples/help\_examples/MPI\_Bcast.m'], 4)

```matlab

if ~MPI_Initialized()
  MPI_Init();
end
my_rank = MPI_Comm_rank();
num_ranks = MPI_Comm_size();
root = 0;
if (my_rank == 0)
  buff = 777;
else
  buff = 0;
end
disp(['rank: ', int2str(my_rank), ': before Bcast, buff is ', int2str(buff)])
buff = MPI_Bcast(buff, root);
disp(['rank: ', int2str(my_rank), ': after Bcast, buff is ', int2str(buff)])
if MPI_Initialized()
  MPI_Finalize();
end

```

## 🔗 See also

[MPI\_Barrier](https://nelson-9.gitbook.io/nelson/markdown/en/mpi/mpi_barrier).

## 🕔 History

| Version | 📄 Description  |
| ------- | --------------- |
| 1.0.0   | initial version |