qq_line_coeffs: Compute a slope and an intercept for a reference line in a...

In GegznaV/BioStat: Routines for Basic (Bio)Statistics

Description

Compute a slope and an intercept for a reference line ("qq-line") in a quantile comparison plot given a vector of data an a theoretical distribution.

Usage

qq_line_coeffs(
  y,
  datax = FALSE,
  distribution = qnorm,
  probs = c(0.25, 0.75),
  qtype = 7,
  na.rm = TRUE,
  ...
)

Arguments

y	(numeric) A numeric vector.
datax	logical. Should data values be on the x-axis?
distribution	quantile function for reference theoretical distribution.
probs	numeric vector of length two, representing probabilities. Corresponding quantile pairs define the line drawn.
qtype	the type of quantile computation used in quantile.
na.rm	logical; if true, any NA and NaN's are removed from x before the quantiles are computed.
...	Further arguments for distribution.

Details

The code is based on code of qqline() in package stats. But instead of plotting a reference line, it returns its coefficients.

Value

A vector with a slope and an intercept for a qq-line.

Examples

set.seed(254)
x <- rnorm(50)

qq_line_coeffs(x)

GegznaV/BioStat documentation built on Aug. 14, 2020, 9:30 p.m.