east = 1
south = 2
west = 3
ndims = 2
steps = [1, 1]
dims = [2, 2]
periods = [False, True]
reorder = False
neighbor = zeros(4, int)
coords = zeros(2, int)
# Create a 2d mpi cart
mpi_cart_create(comm, ndims, dims, periods, reorder, comm_2d, ierr)
# Know my coordinates in the topology
mpi_comm_rank(comm_2d, rank_in_topo, ierr)
mpi_cart_coords(comm_2d, rank_in_topo, ndims, coords, ierr)
# Search of my West and East neigbors
mpi_cart_shift(comm_2d, 0, steps[0], neighbor[west], neighbor[east], ierr)
# Search of my South and North neighbors
mpi_cart_shift(comm_2d, 1, steps[1], neighbor[south], neighbor[north], ierr)
m = 4
v = zeros(m, double)
if coords[0] == 1:
v = (rank + 1) * 1.0
def __init__(self, npts, pads, periods, reorder):
ntx = npts[0]
nty = npts[1]
# ... TODO : to be computed using 'len'
self.ndims = 2
self.n_neighbour = 4
# ...
# ... Constants
north = 0
east = 1
south = 2
west = 3
# ...
# ...
self.neighbour = zeros(self.n_neighbour, int)
self.coords = zeros(self.ndims, int)
self.dims = zeros(self.ndims, int)
self.starts = zeros(self.ndims, int)
self.ends = zeros(self.ndims, int)
self.comm1d = zeros(self.ndims, int)
self.steps = [1, 1]
self.pads = pads
self.periods = periods
self.reorder = reorder
# ...
# ... TODO: remove from here
ierr = -1
size = -1
self.rank = -1
self.rank_in_topo = -1
self.comm_cart = -1
comm = mpi_comm_world
mpi_comm_size(comm, size, ierr)
mpi_comm_rank(comm, self.rank, ierr)
# ...
# ...
# Know the number of processes along x and y
mpi_dims_create(size, self.ndims, self.dims, ierr)
# ...
# ...
# Create a 2d mpi cart
mpi_cart_create(comm, self.ndims, self.dims, self.periods,
self.reorder, self.comm_cart, ierr)
# Know my coordinates in the topology
mpi_comm_rank(self.comm_cart, self.rank_in_topo, ierr)
mpi_cart_coords(self.comm_cart, self.rank_in_topo, self.ndims,
self.coords, ierr)
# X-axis limits
sx = (self.coords[0] * ntx) / self.dims[0]
ex = ((self.coords[0] + 1) * ntx) / self.dims[0] - 1
# Y-axis limits
sy = (self.coords[1] * nty) / self.dims[1]
ey = ((self.coords[1] + 1) * nty) / self.dims[1] - 1
# ...
# ...
self.starts[0] = sx
self.ends[0] = ex
self.starts[1] = sy
self.ends[1] = ey
# ...
# ...
self.sx = sx
self.ex = ex + 1
self.sy = sy
self.ey = ey + 1
# ...
# ... grid without ghost cells
self.r_x = range(self.sx, self.ex, self.steps[0])
self.r_y = range(self.sy, self.ey, self.steps[1])
self.indices = tensor(self.r_x, self.r_y)
# ...
# ...
self.sx_ext = sx - self.pads[0]
self.ex_ext = ex + self.pads[0] + 1
self.sy_ext = sy - self.pads[1]
self.ey_ext = ey + self.pads[1] + 1
# ...
# ... extended grid with ghost cells
self.r_ext_x = range(self.sx_ext, self.ex_ext, self.steps[0])
self.r_ext_y = range(self.sy_ext, self.ey_ext, self.steps[1])
self.extended_indices = tensor(self.r_ext_x, self.r_ext_y)
# ...
# ... Neighbours
# Search of my West and East neigbours
mpi_cart_shift(self.comm_cart, 0, self.pads[0], self.neighbour[west],
self.neighbour[east], ierr)
# Search of my South and North neighbours
mpi_cart_shift(self.comm_cart, 1, self.pads[1], self.neighbour[south],
self.neighbour[north], ierr)
# ...
# ... Create 1d communicator within the cart
flags = [True, False]
mpi_cart_sub(self.comm_cart, flags, self.comm1d[0], ierr)
flags = [False, True]
mpi_cart_sub(self.comm_cart, flags, self.comm1d[1], ierr)
# ...
# ... Derived Types
# Creation of the type_line derived datatype to exchange points
# with northern to southern neighbours
self.type_line = -1
mpi_type_vector(ey - sy + 1, 1, ex - sx + 1 + 2 * self.pads[0],
MPI_DOUBLE, self.type_line, ierr)
mpi_type_commit(self.type_line, ierr)
# Creation of the type_column derived datatype to exchange points
# with western to eastern neighbours
self.type_column = -1
mpi_type_contiguous(ex - sx + 1, MPI_DOUBLE, self.type_column, ierr)
mpi_type_commit(self.type_column, ierr)