plotHist function

Histogram and density plot

Histogram and density plot

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

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.

Returns

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.

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().

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/.

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") }

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()

Author(s)

Alessandro Samuel-Rosa alessandrosamuelrosa@gmail.com