lavaan (version 0.6-16)

InformativeTesting methods: Methods for output InformativeTesting()

Description

The print function shows the results of hypothesis tests Type A and Type B. The plot function plots the distributions of bootstrapped LRT values and plug-in p-values.

Usage

# S3 method for InformativeTesting
print(x, digits = max(3, getOption("digits") - 3), ...)
  
# S3 method for InformativeTesting
plot(x, ..., type = c("lr","ppv"), 
   main = "main", xlab = "xlabel", ylab = "Frequency", freq = TRUE, 
   breaks = 15, cex.main = 1, cex.lab = 1, cex.axis = 1, 
   col = "grey", border = par("fg"), vline = TRUE, 
   vline.col = c("red", "blue"), lty = c(1,2), lwd = 1, 
   legend = TRUE, bty = "o", cex.legend = 1, loc.legend = "topright")

Arguments

x

object of class "InformativeTesting".

digits

the number of significant digits to use when printing.

...

Currently not used.

type

If "lr", a distribution of the first-level bootstrapped LR values is plotted. If "ppv" a distribution of the bootstrapped plug-in p-values is plotted.

main

The main title(s) for the plot(s).

xlab

A label for the x axis, default depends on input type.

ylab

A label for the y axis.

freq

Logical; if TRUE, the histogram graphic is a representation of frequencies, the counts component of the result; if FALSE, probability densities, component density, are plotted (so that the histogram has a total area of one). The default is set to TRUE.

breaks

see hist

cex.main

The magnification to be used for main titles relative to the current setting of cex.

cex.lab

The magnification to be used for x and y labels relative to the current setting of cex.

cex.axis

The magnification to be used for axis annotation relative to the current setting of cex.

col

A colour to be used to fill the bars. The default of NULL yields unfilled bars.

border

Color for rectangle border(s). The default means par("fg").

vline

Logical; if TRUE a vertical line is drawn at the observed LRT value. If double.bootstrap = "FDB" a vertical line is drawn at the 1-p* quantile of the second-level LRT values, where p* is the first-level bootstrapped p-value

vline.col

Color(s) for the vline.LRT.

lty

The line type. Line types can either be specified as an integer (0=blank, 1=solid (default), 2=dashed, 3=dotted, 4=dotdash, 5=longdash, 6=twodash) or as one of the character strings "blank", "solid", "dashed", "dotted", "dotdash", "longdash", or "twodash", where "blank" uses 'invisible lines' (i.e., does not draw them).

lwd

The line width, a positive number, defaulting to 1.

legend

Logical; if TRUE a legend is added to the plot.

bty

A character string which determined the type of box which is drawn about plots. If bty is one of "o" (the default), "l", "7", "c", "u", or "]" the resulting box resembles the corresponding upper case letter. A value of "n" suppresses the box.

cex.legend

A numerical value giving the amount by which the legend text and symbols should be magnified relative to the default. This starts as 1 when a device is opened, and is reset when the layout is changed.

loc.legend

The location of the legend, specified by a single keyword from the list "bottomright", "bottom", "bottomleft", "left", "topleft", "top", "topright", "right" and "center".

Author

Leonard Vanbrabant

Examples

if (FALSE) {
#########################
### real data example ###
#########################
# Multiple group path model for facial burns example.

# model syntax with starting values.
  burns.model <- 'Selfesteem ~ Age + c(m1, f1)*TBSA + HADS +
                             start(-.10, -.20)*TBSA  
                 HADS ~ Age + c(m2, f2)*TBSA + RUM +
                        start(.10, .20)*TBSA '
 
 
# constraints syntax
 burns.constraints <- 'f2 > 0  ; m1 < 0
                       m2 > 0  ; f1 < 0
                       f2 > m2 ; f1 < m1'
 
# we only generate 2 bootstrap samples in this example; in practice
# you may wish to use a much higher number. 
# the double bootstrap was switched off; in practice you probably 
# want to set it to "standard".
example1 <- InformativeTesting(model = burns.model, data = FacialBurns,
                               R = 2, constraints = burns.constraints,
                               double.bootstrap = "no", group = "Sex")
example1
plot(example1)

##########################
### artificial example ###
##########################
# Simple ANOVA model with 3 groups (N = 20 per group)
set.seed(1234)
Y <- cbind(c(rnorm(20,0,1), rnorm(20,0.5,1), rnorm(20,1,1)))
grp <- c(rep("1", 20), rep("2", 20), rep("3", 20))
Data <- data.frame(Y, grp)

#create model matrix
fit.lm <- lm(Y ~ grp, data = Data)
mfit <- fit.lm$model
mm <- model.matrix(mfit)

Y <- model.response(mfit)
X <- data.frame(mm[,2:3])
names(X) <- c("d1", "d2")
Data.new <- data.frame(Y, X)

# model
model <- 'Y ~ 1 + a1*d1 + a2*d2'

# fit without constraints
fit <- sem(model, data = Data.new)

# constraints syntax: mu1 < mu2 < mu3
constraints <- ' a1 > 0
                 a1 < a2 '

# we only generate 10 bootstrap samples in this example; in practice
# you may wish to use a much higher number, say > 1000. The double 
# bootstrap is not necessary in case of an univariate ANOVA model.
example2 <- InformativeTesting(model = model, data = Data.new, 
                               start = parTable(fit),
                               R = 10L, double.bootstrap = "no",
                               constraints = constraints)
example2
# plot(example2)
}