CLUSTEREASY Variables

The new global variables introduced in CLUSTERREASY include

numprocs

The number of processors. (This is determined by the mpirun command or the batch script you use to execute the program.)

my_rank

The rank of each processor. It runs from $0$ to $numprocs-1$.

n

The size of the local grid in the x direction at each processor. The sum of n over all processors should equal N.

my_start_position

The starting point of each processor's grid in the x direction. This will always be zero for the root processor ($my\_rank=0$). For the next processor it will be equal to the value of n on the root processor, and so on.

fstore

This is an extra array used by the root processor to gather field data from other processors. The size of this array is the size of the largest single-field array held by any processor. Note that this array is only cast when checkpointing is turned on or when slices of the same dimension as the grid are being output.

fstore_size

Size of the above array

buffers_up_to_date

This variable indicates whether the buffers at each processor are up to date (1) or not (0). See section 7.4.3 below.