Missing model solutions

Author: jussienko

mpi/simple-datatypes/README.md

@@ -4,7 +4,7 @@ Write a program that sends the highlighted elements of a 2D array
 using user defined datatypes from one MPI task to another. Note the
 different assignments for C and Fortran, and remember that C stores
 arrays in a row-major order and Fortran in a column-major order. You can
-start from skeleton codes in [C](./c) or [Fortran](./fortran)
+start from skeleton codes in [C](skeleton.c) or [Fortran](skeleton.F90)
 
 a) 
 

mpi/simple-datatypes/skeleton.F90

@@ -29,9 +29,11 @@ program datatype1
   end if
 
 
-  !TODO: create datatype describing one row, use mpi_type_vector
+  !TODO: create datatype 
 
-  !TODO: send first row of matrix from rank 0 to 1
+  !TODO: communicate with datatype
+
+  !TODO: free datatype
 
   ! Print out the result
   if (rank == 1) then
@@ -41,7 +43,6 @@ program datatype1
      end do
   end if
 
-  !TODO free datatype
 
   call mpi_finalize(ierr)
 

mpi/simple-datatypes/skeleton.c

@@ -44,7 +44,6 @@ int main(int argc, char **argv)
     //TODO: Free datatype
 
     // Print out the result on rank 1
-    // The application is correct if the first column has the values of rank 0
     if (rank == 1) {
         printf("Received data\n");
         for (i = 0; i < 8; i++) {

mpi/simple-datatypes/solution/custom_type_c.F90

@@ -0,0 +1,58 @@
+program datatype1
+  use mpi_f08
+  implicit none
+
+  integer, dimension(8,8) :: array
+  integer :: rank, ierr
+  type(mpi_datatype) :: subarray
+  integer, dimension(2) :: sizes, subsizes, offsets
+  integer :: i, j
+
+  call mpi_init(ierr)
+  call mpi_comm_rank(MPI_COMM_WORLD, rank ,ierr)
+
+  ! initialize arrays
+  if (rank == 0) then
+     do i=1,8
+        do j=1,8
+           array(i,j) = i*10 + j
+        end do
+     end do
+  else
+     array(:,:) = 0
+  end if
+
+  if (rank == 0) then
+     write(*,*) 'Data in rank 0'
+     do i=1,8
+        write(*,'(8I3)') array(i, :)
+     end do
+  end if
+
+  ! create datatype
+  sizes = 8
+  subsizes = 4
+  offsets = 2
+  call mpi_type_create_subarray(2, sizes, subsizes, offsets, MPI_ORDER_FORTRAN, MPI_INTEGER, subarray, ierr)
+  call mpi_type_commit(subarray, ierr)
+
+  ! send first row of matrix
+  if (rank == 0) then
+     call mpi_send(array(1, 1), 1, subarray, 1, 1, MPI_COMM_WORLD, ierr)
+  else if (rank == 1) then
+     call mpi_recv(array(1, 1), 1, subarray, 0, 1, MPI_COMM_WORLD, MPI_STATUS_IGNORE, &
+          ierr)
+  end if
+
+  ! Print out the result
+  if (rank == 1) then
+     write(*,*) 'Received data'
+     do i=1,8
+        write(*,'(8I3)') array(i, :)
+     end do
+  end if
+
+  call mpi_type_free(subarray, ierr)
+  call mpi_finalize(ierr)
+
+end program datatype1

mpi/simple-datatypes/solution/custom_type_c.c

@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <mpi.h>
+
+int main(int argc, char **argv)
+{
+    int rank;
+    int array[8][8];
+    MPI_Datatype subarray;
+    int i, j;
+
+    MPI_Init(&argc, &argv);
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+
+    // Initialize arrays
+    if (rank == 0) {
+        for (i = 0; i < 8; i++) {
+            for (j = 0; j < 8; j++) {
+                array[i][j] = (i + 1) * 10 + j + 1;
+            }
+        }
+    } else {
+        for (i = 0; i < 8; i++) {
+            for (j = 0; j < 8; j++) {
+                array[i][j] = 0;
+            }
+        }
+    }
+
+    if (rank == 0) {
+        printf("Data in rank 0\n");
+        for (i = 0; i < 8; i++) {
+            for (j = 0; j < 8; j++) {
+                printf("%3d", array[i][j]);
+            }
+            printf("\n");
+        }
+    }
+
+
+    int sizes[2] = {8, 8};
+    int subsizes[2] = {4, 4};
+    int offsets[2] = {2, 2};
+    // Create datatype
+    MPI_Type_create_subarray(2, sizes, subsizes, offsets, MPI_ORDER_C, MPI_INT, &subarray);
+    MPI_Type_commit(&subarray);
+
+    // Send first column of matrix
+    if (rank == 0) {
+        MPI_Send(&array[0][0], 1, subarray, 1, 1, MPI_COMM_WORLD);
+    } else if (rank == 1) {
+        MPI_Recv(&array[0][0], 1, subarray, 0, 1, MPI_COMM_WORLD,
+                 MPI_STATUS_IGNORE);
+    }
+
+    // Print out the result
+    if (rank == 1) {
+        printf("Received data\n");
+        for (i = 0; i < 8; i++) {
+            for (j = 0; j < 8; j++) {
+                printf("%3d", array[i][j]);
+            }
+            printf("\n");
+        }
+    }
+
+    MPI_Type_free(&subarray);
+    MPI_Finalize();
+
+    return 0;
+}