multi.hist {psych}

R Documentation

Multiple histograms with density and normal fits on one page

Description

Given a matrix or data.frame, produce histograms for each variable in a "matrix" form. Include normal fits and density distributions for each plot.

The number of rows and columns may be specified, or calculated. May be used for single variables.

Usage

multi.hist(x,nrow=NULL,ncol=NULL,density=TRUE,freq=FALSE,bcol="white",
      dcol=c("black","black"),dlty=c("dashed","dotted"),
      main=NULL,mar=c(2,1,1,1),breaks=21,global=TRUE,...)
histBy(x,var,group,data=NULL,density=TRUE,alpha=.5,breaks=21,col,xlab,
            main="Histograms by group",freq=FALSE,...) 

Arguments

x	matrix or data.frame
var	The variable in x to plot in histBy
group	The name of the variable in x to use as the grouping variable
data	Needs to be specified if using formula input to histBy
nrow	number of rows in the plot
ncol	number of columns in the plot
density	density=TRUE, show the normal fits and density distributions
freq	freq=FALSE shows probability densities and density distribution, freq=TRUE shows frequencies
bcol	Color for the bars
dcol	The color(s) for the normal and the density fits. Defaults to black.
dlty	The line type (lty) of the normal and density fits. (specify the optional graphic parameter lwd to change the line size)
main	title for each panel will be set to the column name unless specified
mar	Specify the lower, left, upper and right hand side margin in lines – set to be tighter than normal default of c(5,4,4,2) + .1
xlab	Label for the x variable
breaks	The number of breaks in histBy (see hist)
global	If TRUE, use the same x-axis for all plots
alpha	The degree of transparency of the overlapping bars in histBy
col	A vector of colors in histBy (defaults to the rainbow)
...	additional graphic parameters (e.g., col)

Details

This allows for quick summaries of multiple distributions. Particularly useful when examining the results of multiple-split halves that come from the reliability function.

By default, will try to make a square plot with equal number of rows and columns. However, the number of columns and rows may be specified for a particular plot.

Author(s)

William Revelle

See Also

bi.bars for drawing pairwise histograms and scatterHist for bivariate scatter and histograms

Examples

multi.hist(sat.act) 
multi.hist(sat.act,bcol="red")
multi.hist(sat.act,dcol="blue")  #make both lines blue
multi.hist(sat.act,dcol= c("blue","red"),dlty=c("dotted", "solid")) 
multi.hist(sat.act,freq=TRUE)   #show the frequency plot
multi.hist(sat.act,nrow=2)
histBy(sat.act,"SATQ","gender") #input by variable names
histBy(SATQ~ gender, data=sat.act) #formula input

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