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()
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,...)

Arguments

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
... Most graphic parameters may be passed here

Details

These 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. These 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 functions are just a work around for Rgraphviz.

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 1.0-85 Index]