mpi_allreduce对派生数据类型向量的求和。

I'm trying to reduce (sum) a derived data type which is created by MPI_type_vector. When I'm running the code it crashes and complains about the reduction MPI_SUM is not defined for non-instrinsic datatype. I wrote a peice of simple code to show my problem. The code tries to reduce the diagonal elements of a 3*3 matrix:I'm trying to reduce (sum) a derived data type