[R] path.diagram in SEM--display covariances without variances

[Dustin Fife]

Perfect! Thanks for the help.

On Wed, Nov 9, 2011 at 4:27 PM, John Fox <jfox at mcmaster.ca> wrote:
> Dear Dustin,
>
>> -----Original Message-----
>> From: Dustin Fife [mailto:fife.dustin at gmail.com]
>> Sent: November-09-11 2:12 PM
>> To: John Fox
>> Cc: r-help at r-project.org
>> Subject: Re: [R] path.diagram in SEM--display covariances without
>> variances
>>
>> Thanks for the quick response...I've never edited someone else's
>> package before. How do I go about doing that?
>
> I wouldn't change the sem package, but rather create your own version of
> pathDiagram(). You could examine the package sources, but, more simply, to
> see the code for the function, type its name at the command prompt:
>
>> library(sem)
> Loading required package: MASS
> Loading required package: matrixcalc
>> pathDiagram
> function (model, ...)
> {
>    UseMethod("pathDiagram")
> }
> <bytecode: 0000000006E1CEA8>
> <environment: namespace:sem>
>
> So pathDiagram() is a generic function. What methods are available?
>
>> methods(pathDiagram)
> [1] pathDiagram.sem*
>
>   Non-visible functions are asterisked
>
> There is, therefore just one method, for objects of class "sem", hidden in
> the sem namespace. To see it (most lines elided):
>
>> sem:::pathDiagram.sem
> function (model, file, min.rank = NULL, max.rank = NULL, same.rank = NULL,
>    variables = model$var.names, parameters = rownames(model$ram),
>    ignore.double = TRUE, edge.labels = c("names", "values",
>        "both"), size = c(8, 8), node.font = c("Helvetica", 14),
>    edge.font = c("Helvetica", 10), rank.direction = c("LR",
>        "TB"), digits = 2, standardize = FALSE, output.type = c("graphics",
>        "dot"), graphics.fmt = "pdf", dot.options = NULL, ...)
> {
> . . .
>    cat(file = handle, "}\n")
>    if (output.type == "graphics" && !missing(file)) {
>        cmd <- paste("dot -T", graphics.fmt, " -o ", graph.file,
>            " ", dot.options, " ", dot.file, sep = "")
>        cat("Running ", cmd, "\n")
>        result <- try(system(cmd))
>    }
>    invisible(NULL)
> }
> <bytecode: 00000000071B9568>
> <environment: namespace:sem>
>
> Just copy the functions into an editor and make whatever changes you want.
>
> Best,
>  John
>
>>
>> On Wed, Nov 9, 2011 at 12:47 PM, John Fox <jfox at mcmaster.ca> wrote:
>> > Dear Dustin,
>> >
>> >> -----Original Message-----
>> >> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
>> >> project.org] On Behalf Of Dustin Fife
>> >> Sent: November-09-11 10:57 AM
>> >> To: r-help at r-project.org
>> >> Subject: [R] path.diagram in SEM--display covariances without
>> >> variances
>> >>
>> >> Forgive me if I'm posting to the wrong place....It's my first time
>> >> posting.
>> >>
>> >> Here's the situation: I'm using the sem package and making path
>> >> diagrams using path.diagrams. Suppose I have the following code:
>> >>
>> > . . .
>> >
>> >> The diagram is produces is hard to read because of the many
>> variances
>> >> that are shown. The covariance estimates are important for my
>> >> diagram, but the variances are not. Is there a way to suppress the
>> >> variance arrows without suppressing the covariance arrows?
>> >
>> > No, but (1) pathDiagram() (the name of the function in the current
>> > version of the sem package) produces an editable text file, from
>> which
>> > you could remove the arrows that you don't want to see; and (2) you
>> > could modify
>> > pathDiagram() -- the code for the function is, after all, available
>> to
>> > you
>> > -- so that it does what you want.
>> >
>> > I hope this helps,
>> >  John
>> >
>> > --------------------------------
>> > John Fox
>> > Senator William McMaster
>> >  Professor of Social Statistics
>> > Department of Sociology
>> > McMaster University
>> > Hamilton, Ontario, Canada
>> > http://socserv.mcmaster.ca/jfox
>> >
>> >
>> >
>> >>
>> >> --
>> >> Dustin Fife
>> >> Graduate Student, Quantitative Psychology University of Oklahoma
>> >>
>> >> ______________________________________________
>> >> R-help at r-project.org mailing list
>> >> https://stat.ethz.ch/mailman/listinfo/r-help
>> >> PLEASE do read the posting guide http://www.R-project.org/posting-
>> >> guide.html and provide commented, minimal, self-contained,
>> >> reproducible code.
>> >
>> >
>>
>>
>>
>> --
>> Dustin Fife
>> Fife Photography
>> www.fifephotography.com
>> info at fifephotography.com
>> fife.dustin at gmail.com
>> 405.414.5599
>
>



-- 
Dustin Fife
Fife Photography
www.fifephotography.com
info at fifephotography.com
fife.dustin at gmail.com
405.414.5599