plotHist {pedometrics}

Histogram and density plot

Description

Plot a histogram and a density plot of a single variable using the R-package lattice.

Usage

plotHist(
  x,
  HD = "over",
  nint = 20,
  digits = 2,
  stats = TRUE,
  BoxCox = FALSE,
  col = c("lightgray", "black"),
  lwd = c(1, 1),
  lty = "dashed",
  xlim,
  ylim,
  ...
)

plotHD(
  x,
  HD = "over",
  nint = 20,
  digits = 2,
  stats = TRUE,
  BoxCox = FALSE,
  col = c("lightgray", "black"),
  lwd = c(1, 1),
  lty = "dashed",
  xlim,
  ylim,
  ...
)

Arguments

x

Vector of numeric values of the variable for which the histogram and density plot should be created.

HD

Character value indicating the type of plot to be created. Available options are "over", to create a histogram superimposed by the theoretical density plot of a normally distributed variable, and "stack", to create a histogram and an empirical density plot in separated panels. Defaults to HD = "over".

nint

Integer specifying the number of histogram bins. Defaults to nint = 20.

digits

Integer indicating the number of decimal places to be used when printing the statistics of the variable x. Defaults to digits = 2.

stats

Logical to indicate if descriptive statistics of the variable x should be added to the plot. Available only when HD = "over". The function tries to automatically find the best location to put the descriptive statistics given the shape of the histogram. Defaults to stats = TRUE.

BoxCox

Logical to indicate if the variable x should be transformed using the Box-Cox family of power transformations. The estimated lambda value of the Box-Cox transform is printed in the console. It is set to zero when negative. Defaults to BoxCox = FALSE.

col

Vector of two elements, the first indicating the color of the histogram, the second indicating the color of the density plot. Defaults to col = c("lightgray", "black").

lwd

Vector of two elements, the first indicating the line width of the histogram, the second indicating the line width of the density plot. Defaults to lwd = c(1, 1).

lty

Character value indicating the line type for the density plot. Defaults to lty = "dashed".

xlim

Vector of two elements defining the limits of the x axis. The function automatically optimizes xlim based on the density plot.

ylim

Vector of two elements defining the limits of the y axis. The function automatically optimizes ylim based both histogram and density plot.

...

Other arguments that can be passed to lattice functions. There is no guarantee that they will work.

Details

The user should visit the help pages of lattice::histogram(), lattice::densityplot(), lattice::panel.mathdensity(), car::powerTransform(), and car::bcPower() to obtain more details about the main functions used to built plotHD().

Value

An object of class "trellis". The lattice::update.trellis() method can be used to update components of the object and the lattice::print.trellis() print method (usually called by default) will plot it on an appropriate plotting device.

Dependencies

The car package, provider of functions to accompany Fox and Weisberg's An R Companion to Applied Regression, is required for plotHist() to work. The development version of the car package is available on https://r-forge.r-project.org/projects/car/ while its old versions are available on the CRAN archive at https://cran.r-project.org/src/contrib/Archive/car/.

Author(s)

Alessandro Samuel-Rosa [e-mail]

References

Sarkar, Deepayan (2008) Lattice: Multivariate Data Visualization with R, Springer. http://lmdvr.r-forge.r-project.org/

See Also

lattice::histogram(), lattice::densityplot(), lattice::panel.mathdensity()

Examples

if (all(c(require(car), require(lattice), require(latticeExtra)))) {
  x <- rnorm(100, 10, 2)
  p1 <- plotHist(x, HD = "stack")
  p2 <- plotHist(x, HD = "over")
}