matmult {Rmpfr} | R Documentation |
(MPFR) Matrix (Vector) Multiplication
Description
Matrix / vector multiplication of mpfr
(and “simple”
numeric
) matrices and vectors.
matmult (x,y, fPrec = 2)
or
crossprod(x,y, fPrec = 2)
use higher precision in underlying computations.
Usage
matmult(x, y, ...)
Arguments
x, y |
numeric or mpfrMatrix -classed R
objects, i.e. semantically numeric matrices or vectors.
|
... |
arguments passed to the hidden underlying
.matmult.R() work horse which is also underlying the
%*% , crossprod() , and tcrossprod()
methods, see the mpfrMatrix class documentation:
- fPrec
a multiplication factor, a positive number determining
the number of bits precBits used for the underlying
multiplication and summation arithmetic. The default is
fPrec = 1 . Setting fPrec = 2 doubles the
precision which has been recommended, e.g., by John Nash.
- precBits
the number of bits used for the underlying
multiplication and summation arithmetic; by default
precBits = fPrec * max(getPrec(x), getPrec(y)) which
typically uses the same accuracy as regular
mpfr -arithmetic would use.
|
Value
a (base R) matrix
or mpfrMatrix
,
depending on the classes of x
and y
.
Note
Using matmult(x,y)
instead of x %*% y
, makes sense
mainly if you use non-default fPrec
or precBits
arguments.
The crossprod()
, and tcrossprod()
function
have the identical optional arguments fPrec
or precBits
.
Author(s)
Martin Maechler
See Also
%*%
,
crossprod
, tcrossprod
.
Examples
## FIXME: add example
## 1) matmult() <--> %*%
## 2) crossprod() , tcrossprod() %% <--> ./mpfrMatrix-class.Rd examples (!)
[Package
Rmpfr version 0.8-9
Index]