S-Achive: multiply a matrix by a vector

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matvec, vecmat Multiple a matrix by vector

DESCRIPTION

Multiply the rows or columns of a matrix by the elements of a vector.

USAGE

matvec(M, v) vecmat(v, M)

REQUIRED ARGUMENTS

`M`		matrix, or object which can be coerced to a matrix.
`v`		vector, or object which can be coerced to a vector. Length should match the number of columns of M (for matvec) or the number of rows of M (for vecmat)

VALUE

A matrix of the same dimensions as M.

DETAILS

matvec(M,v) is equivalent to M %*% diag(v), while

vecmat(v,M) is equivalent to diag(v) %*% M.

EXAMPLES

> A <- matrix(1:12,3,4)
> A
     [,1] [,2] [,3] [,4]
[1,]    1    4    7   10
[2,]    2    5    8   11
[3,]    3    6    9   12
> matvec(A,c(1,2,3,4))
     [,1] [,2] [,3] [,4]
[1,]    1    8   21   40
[2,]    2   10   24   44
[3,]    3   12   27   48
> vecmat(c(1,2,3),A)
     [,1] [,2] [,3] [,4]
[1,]    1    4    7   10
[2,]    4   10   16   22
[3,]    9   18   27   36

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