The size of a matrix stored as a memuse class object.
nrow,ncol
Number of (global) rows/columns of the matrix.
out.type
If the full dimensions or a reduced representation should be
returned (see Details section below). Options are "full" and "approximate"
(with partial matching).
representation
The kind of storage the object would be in, i.e.
"dense" or "sparse".
...
Additional arguments.
sparsity
The proportion of sparsity of the matrix if
representation="sparse"
type
"double" or "int"; the storage type of the data matrix. If you
don't know the type, it is probably stored as a double, so the default value
will suffice.
intsize
The size (in bytes) of an integer. Default is 4, but this is
platform dependent.
unit.names
string; control for whether the unit names should be
printed out or their abbreviation should be used. Options are "long" and
"short", respectively. Case is ignored.
cores
The number of cores.
par
The type of parallel distribution.
ICTXT
BLACS ICTXT value.
bldim
Blocking dimension for 2d block-cyclic distribution.
Details
This function provides the maximum dimension of an unallocated, dense,
in-core, numeric matrix of known byte size. For example, it will show the
largest possible square matrix which is 16 GiB (46340x46340).
If the both nrow and ncol are missing (blank inputs), then the
largest square matrix will be returned. If one of nrow or
ncol is supplied and the other is missing, then the non-supplied
argument (nrow or ncol) will be determined according to the
supplied one. If both arguments are supplied, an error is produced — you
probably meant to use howmany().
If out.type="approximate", then a reduced representation of the
dimensions will be returned. For example, the reduced representation of the
number 1234567890 would be "1.2b", since this number is basically 1.2
billion. Not super useful, but kind of cute, and it arguably enhances
readability when fishing for a ballpark figure.
Value
howmany() returns a numeric pair, the dimensions of a matrix.
howmany.par() returns a list (the global and local dimensions), each
of which is a numeric pair.
See Also
howbig
Examples
## Not run:
x <- mu(1, "gib")
# largest square matrix that's 1 GiB
howmany(x)
# same, but ballpark figure
howmany(mu(1, "gib"), out.type="approx")
## End(Not run)