| direct.prod {matrixcalc} | R Documentation |
Direct prod of two arrays
Description
This function computes the direct product of two arrays. The arrays can be numerical vectors or matrices. The result is a matrix.
Usage
direct.prod( x, y )
Arguments
x |
a numeric matrix or vector |
y |
a numeric matrix or vector |
Details
If either \bf{x} or \bf{y} is a vector, it is converted to a matrix.
Suppose that \bf{x} is an m \times n matrix and \bf{y} is an p \times q
matrix. Then, the function returns the matrix \left\lbrack {\begin{array}{cccc}
{{x_{1,1}}\;{\bf{y}}}&{{x_{1,2}}\;{\bf{y}}}& \cdots &{{x_{1,n}}\;{\bf{y}}}\\
{{x_{2,1}}\;{\bf{y}}}&{{x_{2,2}}\;{\bf{y}}}& \cdots &{{x_{2,n}}\;{\bf{y}}}\\
\cdots & \cdots & \cdots & \cdots \\
{{x_{m,1}}\;{\bf{y}}}&{{x_{m,2}}\;{\bf{y}}}& \cdots &{{x_{m,n}}\;{\bf{y}}}
\end{array}} \right\rbrack.
Value
A numeric matrix.
Author(s)
Frederick Novomestky fnovomes@poly.edu, Kurt Hornik Kurt.Hornik@wu-wien.ac.at
References
Magnus, J. R. and H. Neudecker (1999) Matrix Differential Calculus with Applications in Statistics and Econometrics, Second Edition, John Wiley.
Examples
x <- matrix( seq( 1, 4 ) )
y <- matrix( seq( 5, 8 ) )
print( direct.prod( x, y ) )