Operators to extract or replace parts of a distributed matrix.
# S4 method for ddmatrix
[(x, i, j, ICTXT)numeric distributed matrix.
indices specifying elements to extract or replace. Indices can
be numeric, character, empty, or NULL.
number of elements for a vector (including lists), rows for a matrix or data
frame or lines for a function. If negative, all but the n last/first
number of elements of x.
optional BLACS context number for output
additional arguments.
Returns a distributed matrix.
[ can be used to extract/replace for a distributed matrix exactly as
you would with an ordinary matrix.
The functions rely on reblocking across different BLACS contexts. If
i is not empty, then the input distributed matrix will be
redistributed along context 1, where extracting/deleting rows does not
destroy block-cyclicality. Likewise, if j is not empty, then the
input distributed matrix will be redistributed along context 2. When
extraction is complete, the matrix will be redistributed across its input
context.