Exclude Node in semPaths {semPlot} - r

Question

I'm trying to plot a sem-path with R.
Im using an OUT file provinent from Mplus with semPaths {semPLot}.
Apparently it seems to work, but i want to remove some latent variables and i don't know how.
I am using the following syntax :
Out from Mplus : https://www.dropbox.com/s/vo3oa5fqp7wydlg/questedMOD2.out?dl=0
outfile1 <- "questedMOD.out"
```
semPaths(outfile1,what="est", intercepts=FALSE, rotation=4, edge.color="black", sizeMan=5, esize=TRUE, structural="TRUE", layout="tree2", nCharNodes=0, intStyle="multi" )

Answer 1

There may be an easier way to do this (and ignoring if it is sensible to do it) - one way you can do this is by removing nodes from the object prior to plotting.
Using the Mplus example from your question Rotate Edges in semPaths/qgraph
library(qgraph)
library(semPlot)
library(MplusAutomation)
# This downloads an output file from Mplus examples
download.file("http://www.statmodel.com/usersguide/chap5/ex5.8.out",
outfile <- tempfile(fileext = ".out"))
# Unadjusted plot
s <- semPaths(outfile, intercepts = FALSE)
In the above call to semPaths, outfile is of class character, so the line (near the start of code for semPaths)
if (!"semPlotModel" %in% class(object))
object <- do.call(semPlotModel, c(list(object), modelOpts))
returns the object from semPlot:::semPlotModel.mplus.model(outfile). This is of class "semPlotModel".
So the idea is to create this object first, amend it and then pass this object to semPaths.
# Call semPlotModel on your Mplus file
obj <- semPlot:::semPlotModel.mplus.model(outfile)
# obj <- do.call(semPlotModel, list(outfile)) # this is more general / not just for Mplus
# Remove one factor (F1) from object#Pars - need to check lhs and rhs columns
idx <- apply(obj#Pars[c("lhs", "rhs")], 1, function(i) any(grepl("F1", i)))
obj#Pars <- obj#Pars[!idx, ]
class(obj)
obj is now of class "semPlotModel" and can be passed directly to semPaths
s <- semPaths(obj, intercepts = FALSE)
You can use str(s) to see the structure of this returned object.

Answer 2

Assuming that you use the following sempath code to print your SEM
semPaths(obj, intercepts = FALSE)%>%
plot()
you can use the following function to remove any node by its label:
remove_nodes_and_edges <- function(semPaths_obj,node_tbrm_vec){
relevent_nodes_index <- semPaths_obj$graphAttributes$Nodes$names %in% node_tbrm_vec
semPaths_obj$graphAttributes$Nodes$width[relevent_nodes_index]=0
semPaths_obj$graphAttributes$Nodes$height[relevent_nodes_index]=0
semPaths_obj$graphAttributes$Nodes$labels[relevent_nodes_index]=""
return(semPaths_obj)
}
and use this function in the plotting pipe in the following way
semPaths(obj, intercepts = FALSE) %>%
remove_nodes_and_edges(c("Y1","Y2","Y3")) %>%
plot()