denPlots a normal density curve and/or a general density curve superimposed over a histogram, all estimated from the data. Also reports the Shapiro-Wilk normality test.
Density(x, dframe=mydata,
bw="nrd0", type=c("both", "general", "normal"),
bin.start=NULL, bin.width=NULL, text.out=TRUE, col.bg=NULL, col.grid=NULL, col.bars=NULL,
col.nrm="black", col.gen="black",
col.fill.nrm=NULL, col.fill.gen=NULL,
colors=c("blue", "gray", "rose", "green", "gold", "red"),
cex.axis=.85, col.axis="gray30", col.ticks="gray30",
x.pt=NULL, xlab=NULL, main=NULL, y.axis=FALSE,
x.min=NULL, x.max=NULL, band=FALSE,
pdf.file=NULL, pdf.width=5, pdf.height=5, ...)
den(...)
mydata.bin.start value.TRUE, then display text output in console."transparent".type=general.TRUE, add a rug plot, a direct display of density in the form of a
narrow band beneath the density curveplot, including xlim, ylim, lwd and cex.lab,
col.main, densitydnorm function and density R functions for estimating densities from data, as well as the hist function for calculating a histogram. Colors are provided by default and can also be specified.The default histogram can be modified with the bin.start and bin.width options. Use the Histogram function in this package for more control over the parameters of the histogram.
The limits for the axes are automatically calculated so as to provide sufficient space for the density curves and histogram, and should generally not require user intervention. Also, the curves are centered over the plot window so that the resulting density curves are symmetric even if the underlying histogram is not. The estimated normal curve is based on the corresponding sample mean and standard deviation.
If x.pt is specified, then type is set to general and y.axis set to TRUE.
DATA
If the variable is in a data frame, the input data frame has the assumed name of mydata. If this data frame is named something different, then specify the name with the dframe option. Regardless of its name, the data frame need not be attached to reference the variable directly by its name, that is, no need to invoke the mydata$name notation.
COLOR THEME
Individual colors in the plot can be manipulated with options such as col.bars for the color of the histogram bars. A color theme for all the colors can be chosen for a specific plot with the colors option. Or, the color theme can be changed for all subsequent graphical analysis with the lessR function set. The default color theme is blue, but a gray scale is available with "gray", and other themes are available as explained in set.
VARIABLE LABELS
Although standard R does not provide for variable labels, lessR can store the labels in a data frame called mylabels, obtained from the Read function. If this labels data frame exists, then the corresponding variable label is by default listed as the label for the horizontal axis and on the text output. For more information, see Read.
PDF OUTPUT
Because of the customized graphic windowing system that maintains a unique graphic window for the Help function, the standard graphic output functions such as pdf do not work with the lessR graphics functions. Instead, to obtain pdf output, use the pdf.file option, perhaps with the optional pdf.width and pdf.height options. These files are written to the default working directory, which can be explicitly specified with the R setwd function.
ONLY VARIABLES ARE REFERENCED
The referenced variable in a lessR function can only be a variable name. This referenced variable must exist in either the referenced data frame, mydata by default, or in the user's workspace, more formally called the global environment. That is, expressions cannot be directly evaluated. For example:
> Density(rnorm(50)) # does NOT work}
Instead, do the following: > Y <- rnorm(50) # create vector Y in user workspace > Density(Y) # directly reference Y
[object Object],[object Object]
dnorm, density, hist, plot, rgb, shapiro.test.
# normal curve and general density curves superimposed over histogram # all defaults Density(y)
# short name den(y)
# save the density plot to a pdf file Density(y, pdf.file="MyDensityPlot.pdf")
# suppress the histogram, leaving only the density curves # specify x-axis label per the xlab option for the plot function Density(y, col.bars="transparent", xlab="My Var")
# specify (non-transparent) colors for the curves, # to make transparent, need alpha option for the rgb function Density(y, col.nrm="darkgreen", col.gen="plum")
# display only the general estimated density # so do not display the estimated normal curve # specify the bandwidth for the general density curve, # use the standard bw option for the density function Density(y, type="general", bw=.6)
# display only the general estimated density and a corresponding # interval of unit width around x.pt Density(y, type="general", x.pt=2)
# create data frame, mydata, to mimic reading data with rad function # although data not attached, access the variable directly by its name mydata <- data.frame(rnorm(100)) names(mydata) <- "X" Density(X)
# variable of interest is in a data frame which is not the default mydata
# access the breaks variable in the R provided warpbreaks data set
# although data not attached, access the variable directly by its name
data(warpbreaks)
Density(breaks, dframe=warpbreaks)