as.mxAlgebra {metaSEM}

Convert a Character Matrix into MxAlgebra-class

Description

It converts a character matrix into MxAlgebra object.

Usage

as.mxAlgebra(x, startvalues=NULL, name="X")

Arguments

x

A character or numeric matrix, which consists of valid operators in mxAlgebra.

startvalues

A list of starting values of the free parameters. If it is not provided, all free parameters are assumed 0.

name

A character string of the names of the objects based on.

Details

Suppose the name argument is "X", the output is a list of the following elements.

Value

mxalgebra

An mxAlgebra object.

parameters

A column vector mxMatrix of the free parameters.

list

A list of mxMatrix to form the mxAlgebra object.

Author(s)

Mike W.-L. Cheung <[e-mail]>

See Also

as.mxMatrix, mxAlgebra

Examples

## a, b, and c are free parameters
(A1 <- matrix(c(1, "a*b", "a^b", "exp(c)"), ncol=2, nrow=2))
##      [,1]  [,2]    
## [1,] "1"   "a^b"   
## [2,] "a*b" "exp(c)"

A <- as.mxAlgebra(A1, startvalues=list(a=1, b=2), name="A")

## An object of mxAlgebra
A$mxalgebra
## mxAlgebra 'A' 
## $formula:  rbind(cbind(A1_1, A1_2), cbind(A2_1, A2_2)) 
## $result: (not yet computed) <0 x 0 matrix>
## dimnames: NULL

## A matrix of parameters
A$parameters
## FullMatrix 'Avars' 

## $labels
##      [,1]
## [1,] "a" 
## [2,] "b" 
## [3,] "c" 

## $values
##      [,1]
## [1,] 1   
## [2,] 2   
## [3,] 0   

## $free
##      [,1]
## [1,] TRUE
## [2,] TRUE
## [3,] TRUE

## $lbound: No lower bounds assigned.

## $ubound: No upper bounds assigned.


## A list of matrices of elements for the mxAlgebra
A$list
## $A1_1
## mxAlgebra 'A1_1' 
## $formula:  1 
## $result: (not yet computed) <0 x 0 matrix>
## dimnames: NULL

## $A2_1
## mxAlgebra 'A2_1' 
## $formula:  a * b 
## $result: (not yet computed) <0 x 0 matrix>
## dimnames: NULL

## $A1_2
## mxAlgebra 'A1_2' 
## $formula:  a^b 
## $result: (not yet computed) <0 x 0 matrix>
## dimnames: NULL

## $A2_2
## mxAlgebra 'A2_2' 
## $formula:  exp(c) 
## $result: (not yet computed) <0 x 0 matrix>
## dimnames: NULL