error.dots: Show a dot.chart with error bars for different groups or...

In psych: Procedures for Psychological, Psychometric, and Personality Research

Show a dot.chart with error bars for different groups or variables

Description

Yet one more of the graphical ways of showing data with error bars for different groups. A dot.chart with error bars for different groups or variables is found using from describe, describeBy, statsBy, corCi, corr.test or data from bestScales.

Usage

error.dots(x=NULL, var = NULL, se = NULL, group = NULL, sd = FALSE, effect=NULL,
stats=NULL, head = 12, tail = 12, sort = TRUE, decreasing = TRUE, main = NULL,
 alpha = 0.05, eyes = FALSE,items=FALSE, min.n = NULL, max.labels = 40, labels = NULL,
 label.width=NULL, select=NULL,
 groups = NULL, gdata = NULL, cex =  par("cex"),  pt.cex = cex, pch = 21, gpch = 21, 
 bg = par("bg"), fg=par("fg"), color = par("fg"), gcolor = par("fg"), 
 lcolor = "gray", xlab = NULL, ylab = NULL, xlim = NULL,add=FALSE,order=NULL, ...)

Arguments

x	A data frame or matrix of raw data, or the resulting object from describe, describeBy, statsBy, bestScales, corCi, corr.test, or cohen.d
var	The variable to show (particularly if doing describeBy or StatsBy plots).
se	Source of a standard error
group	A grouping variable, if desired. Will group the data on group for one variable (var)
sd	if FALSE, confidence intervals in terms of standard errors, otherwise draw one standard deviation
effect	Should the data be compared to a specified group (with mean set to 0) in effect size units?
stats	A matrix of means and se to use instead of finding them from the data
head	The number of largest values to report
tail	The number of smallest values to report
sort	Sort the groups/variables by value
decreasing	Should they be sorted in increasing or decreasing order (from top to bottom)
main	The caption for the figure
alpha	p value for confidence intervals
eyes	Draw catseyes for error limits
items	If showing results from best scales, show the items for a specified dv
min.n	If using describeBy or statsBy, what should be the minimum sample size to draw
max.labels	Length of labels (truncate after this value)
labels	Specify the labels versus find them from the row names
label.width	Truncate after labels.width
select	Scale the plot for all the variables, but just show the select variables
groups	ignored: to be added eventually
gdata	ignored
cex	The standard meaning of cex for graphics
pt.cex	ignored
pch	Plot character of the mean
gpch	ignored
bg	background color (of the dots showing the means)
fg	foreground color (of the line segments)
color	Color of the text labels
gcolor	ignored
lcolor	ignored until groups are implemented
xlab	Label the x axis, if NULL, the variable name is used
ylab	If NULL, then the group rownames are used
xlim	If NULL, then calculated to show nice values
add	If TRUE, will add the plot to a previous plot (e.g., from dotchart)
order	if sort=TRUE, if order is NULL, sort on values, otherwise, if order is returned from a previous figure, use that order.
...	And any other graphic parameters we have forgotten

Details

Adapted from the dot.chart function to include error bars and to use the output of describe, describeBy, statsBy, fa, bestScales or cohen.d. To speed up multiple plots, the function can work from the output of a previous run. Thus describeBy will be done and the results can be show for multiple variables.

If using the add=TRUE option to add an error.dots plot to a dotplot, note that the order of variables in dot plots goes from last to first (highest y value is actually the last value in a vector.) Also note that the xlim parameter should be set to make sure the plots line up correctly.

Value

Returns (invisibily) either a describeBy or describe object as well as the order if sorted

Author(s)

William Revelle

References

Used in particular for showing https://sapa-project.org output.

See Also

describe, describeBy, or statsBy as well as error.bars, error.bars.by, statsBy, bestScales or cohen.d

Examples

temp <- error.dots(bfi[1:25],sort=TRUE, 
xlab="Mean score for the item, sorted by difficulty")
error.dots(bfi[1:25],sort=TRUE, order=temp$order,
 add=TRUE, eyes=TRUE) #over plot with eyes

#error.dots(psychTools::ability,eyes=TRUE, xlab="Mean score for the item")

cd <- cohen.d(bfi[1:26],"gender")
temp <- error.dots(cd, select=c(1:15,21:25),head=12,tail=13,
      main="Cohen d and confidence intervals of BFI by gender")
error.dots(cd,select=c(16:20),head=13,tail=12,col="blue",add=TRUE,fg="red" ,main="")
abline(v=0)
#now show cis for correlations
R <- corCi(attitude,plot=FALSE)
error.dots(R, sort=FALSE)
#the asymmetric case
R <- corr.test(attitude[,1:2],attitude[,3:7])
error.dots(R, sort=FALSE)

psych documentation built on June 27, 2024, 5:07 p.m.