path.diagram: Draw Path Diagram

Description

path.diagram creates a description of the path diagram for a structural-equation-model object to be processed by the graph-drawing program dot; see Koutsofios and North (1996) and http://www.research.att.com/sw/tools/graphviz/.

Usage

path.diagram(model, ...)

## S3 method for class 'sem':
path.diagram(model, out.file, min.rank=NULL, max.rank=NULL, 
    same.rank=NULL, variables=model$var.names, parameters=rownames(object$ram), 
    ignore.double=TRUE, edge.labels=c("names", "values"), size=c(8, 8), 
    node.font=c("Helvetica", 14), edge.font=c("Helvetica", 10), 
    rank.direction=c("LR", "TB"), ...)

Arguments

model

a structural-equation-model object produced by sem.

...

arguments to be passed down to path.diagram.sem.

out.file

a file to which to write the dot description of the path diagram; if not specified, the description is written to standard output (normally the R Console).

min.rank

a character string listing names of variables to be assigned minimum rank (order) in the graph; the names should be separated by commas.

max.rank

a character string listing names of variables to be assigned maximum rank in the graph; the names should be separated by commas.

same.rank

a character string or vector of character strings of variables to be assigned equivalent rank in the graph; names in each string should be separated by commas.

variables

variable names; defaults to the variable names in model. If specified, the variable names should be in the same order as in model.

parameters

parameter names; defaults to the parameter names in model. If specified, the parameter names should be in the same order as in model.

ignore.double

if TRUE, the default, double-headed arrows, representing variances and covariances, are not graphed.

edge.labels

"names" to label arrows with parameter names; "values" to label arrows with parameter estimates.

size

the size of the graph, in inches.

node.font

font name and point-size for printing variable names.

edge.font

font name and point-size for printing arrow names or values.

rank.direction

draw graph left-to-right, "LR", the default, or top-to-bottom, "TB".

Value

NULL: path.diagram is used for its side-effect, producing a graph description of the model.

References

Koutsofios, E., and North, S. C. (1996) Drawing graphs with dot. http://www.research.att.com/sw/tools/graphviz/dotguide.pdf.

Examples

Run this code

# The Duncan, Haller, and Portes Peer-Influences Model

R.DHP <- matrix(c(     
            1,      0,      0,      0,      0,      0,      0,      0,      0,      0,            
            .6247,   1,     0,      0,      0,      0,      0,      0,      0,      0,            
            .3269,  .3669,  1,      0,      0,      0,      0,      0,      0,      0,            
            .4216,  .3275,  .6404,  1,      0,      0,      0,      0,      0,      0,
            .2137,  .2742,  .1124,  .0839,  1,      0,      0,      0,      0,      0,
            .4105,  .4043,  .2903,  .2598,  .1839,  1,      0,      0,      0,      0,
            .3240,  .4047,  .3054,  .2786,  .0489,  .2220,  1,      0,      0,      0,
            .2930,  .2407,  .4105,  .3607,  .0186,  .1861,  .2707,  1,      0,      0,
            .2995,  .2863,  .5191,  .5007,  .0782,  .3355,  .2302,  .2950,  1,      0,
            .0760,  .0702,  .2784,  .1988,  .1147,  .1021,  .0931, -.0438,  .2087,  1
            ), ncol=10, byrow=TRUE)

model.dhp <- matrix(c(
                      'RParAsp  -> RGenAsp', 'gam11',  NA,
                      'RIQ      -> RGenAsp', 'gam12',  NA,
                      'RSES     -> RGenAsp', 'gam13',  NA,
                      'FSES     -> RGenAsp', 'gam14',  NA,
                      'RSES     -> FGenAsp', 'gam23',  NA,
                      'FSES     -> FGenAsp', 'gam24',  NA,
                      'FIQ      -> FGenAsp', 'gam25',  NA,
                      'FParAsp  -> FGenAsp', 'gam26',  NA,
                      'FGenAsp  -> RGenAsp', 'beta12', NA,
                      'RGenAsp  -> FGenAsp', 'beta21', NA,
                      'RGenAsp  -> ROccAsp',  NA,       1,
                      'RGenAsp  -> REdAsp',  'lam21',  NA,
                      'FGenAsp  -> FOccAsp',  NA,       1,
                      'FGenAsp  -> FEdAsp',  'lam42',  NA,
                      'RGenAsp <-> RGenAsp', 'ps11',   NA,
                      'FGenAsp <-> FGenAsp', 'ps22',   NA,
                      'RGenAsp <-> FGenAsp', 'ps12',   NA,
                      'ROccAsp <-> ROccAsp', 'theta1', NA,
                      'REdAsp  <-> REdAsp',  'theta2', NA,
                      'FOccAsp <-> FOccAsp', 'theta3', NA,
                      'FEdAsp  <-> FEdAsp',  'theta4', NA),
                    ncol=3, byrow=TRUE)

rownames(R.DHP) <- colnames(R.DHP) <- c('ROccAsp', 'REdAsp', 'FOccAsp', 
    'FEdAsp', 'RParAsp', 'RIQ', 'RSES', 'FSES', 'FIQ', 'FParAsp')

sem.dhp <- sem(model.dhp, R.DHP, 329,
    fixed.x=c('RParAsp', 'RIQ', 'RSES', 'FSES', 'FIQ', 'FParAsp'))
    
path.diagram(sem.dhp, min.rank='RIQ, RSES, RParAsp, FParAsp, FSES, FIQ', 
    max.rank='ROccAsp, REdAsp, FEdAsp, FOccAsp')

##   digraph "sem.dhp" {
##   rankdir=LR;
##   size="8,8";
##   node [fontname="Helvetica" fontsize=14 shape=box];
##   edge [fontname="Helvetica" fontsize=10];
##   center=1;
##   {rank=min "RIQ" "RSES" "RParAsp" "FParAsp" "FSES" "FIQ"}
##   {rank=max "ROccAsp" "REdAsp" "FEdAsp" "FOccAsp"}
##   "RGenAsp" [shape=ellipse]
##   "FGenAsp" [shape=ellipse]
##   "RParAsp" -> "RGenAsp" [label="gam11"];
##   "RIQ" -> "RGenAsp" [label="gam12"];
##   "RSES" -> "RGenAsp" [label="gam13"];
##   "FSES" -> "RGenAsp" [label="gam14"];
##   "RSES" -> "FGenAsp" [label="gam23"];
##   "FSES" -> "FGenAsp" [label="gam24"];
##   "FIQ" -> "FGenAsp" [label="gam25"];
##   "FParAsp" -> "FGenAsp" [label="gam26"];
##   "FGenAsp" -> "RGenAsp" [label="beta12"];
##   "RGenAsp" -> "FGenAsp" [label="beta21"];
##   "RGenAsp" -> "ROccAsp" [label=""];
##   "RGenAsp" -> "REdAsp" [label="lam21"];
##   "FGenAsp" -> "FOccAsp" [label=""];
##   "FGenAsp" -> "FEdAsp" [label="lam42"];
##   }