mxalgebra-help

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Usage

mxAlgebra(expression, name = NA, dimnames = NA)

mxAlgebra() allows you create algebraic expressions based on one or more MxMatrix objects.

Legal functions within an algebra are described here.

	A <- mxMatrix("Full", nrow = 3, ncol = 3, values=1:9, name = "A")
	B <- mxAlgebra(A, name = "B")
	C <- mxAlgebra(A + B, name = "C")
	D <- mxAlgebra(sin(C), name = "D")
 
	model <- mxModel("AlgebraExample", A, B, C, D )
	fit   <- mxRun(model)
 
	mxEval(AlgebraExample.D, fit)
	#           [,1]       [,2]       [,3]
	# [1,]  0.9092974  0.9893582  0.9906074
	# [2,] -0.7568025 -0.5440211 -0.2879033
	# [3,] -0.2794155 -0.5365729 -0.7509872

Gotchas

A common misunderstanding is to call mxAlgebra() expecting it to be evaluated without subsequently being placed in a model and run as above. To evaluate an MxAlgebra, it must be placed in an MxModel (along with all referenced MxMatrix objects) and run.

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