exams.forge (version 1.0.10)

histdata: Histogram Data

Description

Returns data for a histogram. Calls internally hist(..., plot=FALSE).

• mean returns the mean of the data.

• quantile and median return the quantile(s) or median with an attribute pos, the class number of the quantile(s), or the median.

Usage

histdata(x, breaks = "Sturges", probs = seq(0, 1, 0.25), ...)
# S3 method for histogram
quantile(x, probs = seq(0, 1, 0.25), ...)
# S3 method for histogram
median(x, ...)
# S3 method for histogram
mean(x, ...)
dhist(x, breaks = "Sturges", probs = seq(0, 1, 0.25), ...)

Value

Like in graphics::hist, but with this additional list of elements:

• lower lower class borders,

• upper upper class borders,

• width class widths,

• relfreq the relative class frequency,

• cumfbrk the cumulated relative frequency of the breaks,

• maxdens the indices of the maximal density values,

• maxcount the indices of the maximal count values

• x the original finite data, and

• class the class number for each value in x.

Arguments

x

numeric data or histogram data

breaks

one of:

• a vector giving the breakpoints between histogram cells,

• a function to compute the vector of breakpoints,

• a single number giving the number of cells for the histogram,

• a character string naming an algorithm to compute the number of cells (see ‘Details’),

• a function to compute the number of cells.

In the last three cases the number is a suggestion only; as the breakpoints will be set to pretty values, the number is limited to 1e6 (with a warning if it was larger). If breaks is a function, the x vector is supplied to it as the only argument (and the number of breaks is only limited by the amount of available memory).

probs

numeric: probabilities to use if breaks="Quantile" (default: seq(0, 1, 0.25))

...

further parameters used in graphics::hist

Examples

#1
x <- seq(0, 1, by=0.25)
print(hist(x, plot=FALSE))
histdata(x)
#2
x <- seq(0, 1, by=0.25)
print(hist(x, x, plot=FALSE))
histdata(x, x)
#3
print(hist(x, x, right=FALSE, plot=FALSE))
histdata(x, x, right=FALSE)