diagram {psych}R Documentation

Helper functions for drawing path model diagrams

Description

Path models are used to describe structural equation models or cluster analytic output. These functions provide the primitives for drawing path models. Used as a substitute for some of the functionality of Rgraphviz.

Usage

diagram(fit,...)
dia.rect(x, y = NULL, labels = NULL,  cex = 1,  xlim = c(0, 1), ylim = c(0, 1), ...)
 dia.ellipse(x, y = NULL, labels = NULL, cex=1,e.size=.05, xlim=c(0,1), 
           ylim=c(0,1),  ...) 
 dia.triangle(x, y = NULL, labels =NULL,  cex = 1, xlim=c(0,1),ylim=c(0,1),...)
dia.ellipse1(x,y,e.size=.05,xlim=c(0,1),ylim=c(0,1),...)
dia.shape(x, y = NULL, labels = NULL, cex = 1, e.size=.05, 
         xlim=c(0,1), ylim=c(0,1), shape=1, ...)
dia.arrow(from,to,labels=NULL,scale=1,cex=1,...)
dia.curve(from,to,labels=NULL,scale=1,...)
dia.curved.arrow(from,to,labels=NULL,scale=1,...)
dia.self(location,labels=NULL,scale=.8,side=2,...)
dia.cone(x=0, y=-2, theta=45, arrow=TRUE,curves=TRUE,add=FALSE,labels=NULL,
      xlim = c(-1, 1), ylim=c(-1,1),... ) 

Arguments

fit

The results from a factor analysis fa, components analysis principal, omega reliability analysis, omega, cluster analysis iclust or confirmatory factor analysis, cfa, or structural equation model,sem, using the lavaan package.

x

x coordinate of a rectangle or ellipse

y

y coordinate of a rectangle or ellipse

e.size

The size of the ellipse (scaled by the number of variables

labels

Text to insert in rectangle, ellipse, or arrow

cex

adjust the text size

scale

modifies size of rectangle and ellipse as well as the curvature of curves. (For curvature, positive numbers are concave down and to the left

from

arrows and curves go from

to

arrows and curves go to

location

where is the rectangle?

shape

Which shape to draw

xlim

default ranges

ylim

default ranges

side

Which side of boxes should errors appear

theta

Angle in degrees of vectors

arrow

draw arrows for edges in dia.cone

add

if TRUE, plot on previous plot

curves

if TRUE, draw curves between arrows in dia.cone

...

Most graphic parameters may be passed here

Details

The diagram function calls fa.diagram, omega.diagram, ICLUST.diagram or lavaan.diagram depending upon the class of the fit input. See those functions for particular parameter values.

The remaining functions are the graphic primitives used by fa.diagram, structure.diagram, omega.diagram, and ICLUST.diagram.

They create rectangles, ellipses or triangles surrounding text, connect them to straight or curved arrows, and can draw an arrow from and to the same rectangle.

Each shape (ellipse, rectangle or triangle) has a left, right, top and bottom and center coordinate that may be used to connect the arrows.

Curves are double-headed arrows.

The helper functions were developed to get around the infelicities associated with trying to install Rgraphviz and graphviz.

Better documentation will be added as these functions get improved. Currently the helper functions are just a work around for Rgraphviz.

dia.cone draws a cone with (optionally) arrows as sides and centers to show the problem of factor indeterminacy.

Value

Graphic output

Author(s)

William Revelle

See Also

The diagram functions that use the dia functions: fa.diagram, structure.diagram, omega.diagram, and ICLUST.diagram.

Examples

#first, show the primitives
xlim=c(-2,10)
ylim=c(0,10)
plot(NA,xlim=xlim,ylim=ylim,main="Demonstration of diagram functions",axes=FALSE,xlab="",ylab="")
ul <- dia.rect(1,9,labels="upper left",xlim=xlim,ylim=ylim)
ml <- dia.rect(1,6,"middle left",xlim=xlim,ylim=ylim)
ll <- dia.rect(1,3,labels="lower left",xlim=xlim,ylim=ylim)
bl <- dia.rect(1,1,"bottom left",xlim=xlim,ylim=ylim)
lr <- dia.ellipse(7,3,"lower right",xlim=xlim,ylim=ylim,e.size=.07)
ur <- dia.ellipse(7,9,"upper right",xlim=xlim,ylim=ylim,e.size=.07)
mr <- dia.ellipse(7,6,"middle right",xlim=xlim,ylim=ylim,e.size=.07)
lm <- dia.triangle(4,1,"Lower Middle",xlim=xlim,ylim=ylim)
br <- dia.rect(9,1,"bottom right",xlim=xlim,ylim=ylim) 
dia.curve(from=ul$left,to=bl$left,"double headed",scale=-1)

dia.arrow(from=lr,to=ul,labels="right to left")
dia.arrow(from=ul,to=ur,labels="left to right")
dia.curved.arrow(from=lr,to=ll,labels ="right to left")
dia.curved.arrow(to=ur,from=ul,labels ="left to right")
dia.curve(ll$top,ul$bottom,"right")  #for rectangles, specify where to point 

dia.curve(ll$top,ul$bottom,"left",scale=-1)  #for rectangles, specify where to point 
dia.curve(mr,ur,"up")  #but for ellipses, you may just point to it.
dia.curve(mr,lr,"down")
dia.curve(mr,ur,"up")
dia.curved.arrow(mr,ur,"up")  #but for ellipses, you may just point to it.
dia.curved.arrow(mr,lr,"down")  #but for ellipses, you may just point to it.

dia.curved.arrow(ur$right,mr$right,"3")
dia.curve(ml,mr,"across")
dia.curve(ur,lr,"top down")
dia.curved.arrow(br$top,lr$bottom,"up")
dia.curved.arrow(bl,br,"left to right")
dia.curved.arrow(br,bl,"right to left",scale=-1)
dia.arrow(bl,ll$bottom)
dia.curved.arrow(ml,ll$right)
dia.curved.arrow(mr,lr$top)

#now, put them together in a factor analysis diagram
v9 <- sim.hierarchical()
f3 <- fa(v9,3,rotate="cluster")
fa.diagram(f3,error=TRUE,side=3) 

[Package psych version 1.4.5 Index]
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