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Create a function to generate mxMatrix and mxAlgebra

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No user picture. Veronica_echo Joined: 02/23/2018
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OpenMx General Help

Hi everyone,

I am writing an R function which can create and run an OpenMx model. I can do it in a simple way. Partial codes are shown below. However, I have over 20 definition variables and for each I need corresponding mxAlgebra. I may want to write a function/a loop to generate mxMatrix and mxAlgebra. I've tried a couple of methods, yet none of them worked. The mainly problem is that in the expression of mxAlgebra, I need call the name of corresponding mxMatrix. Thank you in advance!

mxMatrix("Full", 1, 1, free = T, values = 7, labels = "mu", name = "g"),
mxMatrix("Full", 1, 1, free = F, labels = "data.T1", name = "t1"),
mxMatrix("Full", 1, 1, free = F, labels = "data.T2", name = "t2"),
mxMatrix("Full", 1, 1, free = F, labels = "data.T3", name = "t3"),
mxMatrix("Full", 1, 1, free = F, labels = "data.T4", name = "t4"),
...
mxAlgebra(abs(t1 - g), name = "L20"),
mxAlgebra(abs(t2 - g), name = "L21"),
mxAlgebra(abs(t3 - g), name = "L22"),
mxAlgebra(abs(t4 - g), name = "L23"),
...

Replied on Sun, 03/25/2018 - 12:24
Picture of user. mhunter Joined: 07/31/2009

To elaborate on what Joshua wrote


mlist <- list()
alist <- list()
maxt <- 5
for(i in 1:maxt){
mlist[[i]] <- mxMatrix('Full', 1, 1, free=FALSE, labels=paste0('data.T', i), name=paste0('t', i))
alist[[i]] <- mxAlgebraFromString(paste0("abs(t", i, " - g)"), name=paste0("L2", i-1))
}

This creates `mlist`, a list of MxMatrix objects, and `alist`, a list of MxAlgebra objects.


> mlist
[[1]]
FullMatrix 't1'

$labels
[,1]
[1,] "data.T1"

$values
[,1]
[1,] 0

$free: No free parameters.

$lbound: No lower bounds assigned.

$ubound: No upper bounds assigned.

[[2]]
FullMatrix 't2'

$labels
[,1]
[1,] "data.T2"

$values
[,1]
[1,] 0

$free: No free parameters.

$lbound: No lower bounds assigned.

$ubound: No upper bounds assigned.

[[3]]
FullMatrix 't3'

$labels
[,1]
[1,] "data.T3"

$values
[,1]
[1,] 0

$free: No free parameters.

$lbound: No lower bounds assigned.

$ubound: No upper bounds assigned.

[[4]]
FullMatrix 't4'

$labels
[,1]
[1,] "data.T4"

$values
[,1]
[1,] 0

$free: No free parameters.

$lbound: No lower bounds assigned.

$ubound: No upper bounds assigned.

[[5]]
FullMatrix 't5'

$labels
[,1]
[1,] "data.T5"

$values
[,1]
[1,] 0

$free: No free parameters.

$lbound: No lower bounds assigned.

$ubound: No upper bounds assigned.

> alist
[[1]]
mxAlgebra 'L20'
$formula: abs(t1 - g)
$result: (not yet computed) <0 x 0 matrix>
dimnames: NULL

[[2]]
mxAlgebra 'L21'
$formula: abs(t2 - g)
$result: (not yet computed) <0 x 0 matrix>
dimnames: NULL

[[3]]
mxAlgebra 'L22'
$formula: abs(t3 - g)
$result: (not yet computed) <0 x 0 matrix>
dimnames: NULL

[[4]]
mxAlgebra 'L23'
$formula: abs(t4 - g)
$result: (not yet computed) <0 x 0 matrix>
dimnames: NULL

[[5]]
mxAlgebra 'L24'
$formula: abs(t5 - g)
$result: (not yet computed) <0 x 0 matrix>
dimnames: NULL

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