qqplot and qqnorm
qqplot(x, y; kwargs...)
Draw a Q-Q plot, comparing quantiles of two distributions.
y
must be a list of samples, i.e.,
AbstractVector{<:Real}
, whereas
x
can be
-
a list of samples,
-
an abstract distribution, e.g.
Normal(0, 1)
, -
a distribution type, e.g.
Normal
.
In the last case, the distribution type is fitted to the data
y
.
The attribute
qqline
(defaults to
:none
) determines how to compute a fit line for the Q-Q plot. Possible values are the following.
-
:identity
draws the identity line. -
:fit
computes a least squares line fit of the quantile pairs. -
:fitrobust
computes the line that passes through the first and third quartiles of the distributions. -
:none
omits drawing the line.
Broadly speaking,
qqline = :identity
is useful to see if
x
and
y
follow the same distribution, whereas
qqline = :fit
and
qqline = :fitrobust
are useful to see if the distribution of
y
can be obtained from the distribution of
x
via an affine transformation.
Graphical attributes are
-
color
to control color of both line and markers (ifmarkercolor
is not specified) -
linestyle
-
linewidth
-
markercolor
-
strokecolor
-
strokewidth
-
marker
-
markersize
qqnorm(y; kwargs...)
Shorthand for
qqplot(Normal(0,1), y)
, i.e., draw a Q-Q plot of
y
against the standard normal distribution. See
qqplot
for more details.
Examples
Test if
xs
and
ys
follow the same distribution.
using CairoMakie
xs = randn(100)
ys = randn(100)
qqplot(xs, ys, qqline = :identity)
Test if
ys
is normally distributed.
using CairoMakie
ys = 2 .* randn(100) .+ 3
qqnorm(ys, qqline = :fitrobust)
These docs were autogenerated using Makie: v0.17.13, GLMakie: v0.6.13, CairoMakie: v0.8.13, WGLMakie: v0.6.13