Histogram with a normal curve

Produces a histogram for a vector of values and adds a normal curve with the same mean and standard deviation. The plot can be used to quickly compare the distribution of data to a normal distribution.

Usage

plotNormalHistogram(
  x,
  prob = FALSE,
  col = "gray",
  main = "",
  linecol = "blue",
  lwd = 2,
  length = 1000,
  ...
)

Arguments

x: A vector of values.
prob: If FALSE, then counts are displayed in the histogram. If TRUE, then the density is shown.
col: The color of the histogram bars.
main: The title displayed for the plot.
linecol: The color of the line in the plot.
lwd: The width of the line in the plot.
length: The number of points in the line in the plot.
...: Other arguments passed to hist.

Value

Produces a plot. Returns nothing.

Details

The function relies on the hist function. The normal curve has the same mean and standard deviation as the values in the vector.

References

https://rcompanion.org/handbook/I_01.html

Author

Salvatore Mangiafico, mangiafico@njaes.rutgers.edu

Examples

### Plot of residuals from a model fit with lm
data(Catbus)
model = lm(Steps ~ Gender + Teacher,
           data = Catbus)
 plotNormalHistogram(residuals(model))