plotqq
Purpose
Quantile-quantile plot.
Synopsis
vals = plotqq(x,distname,options)
Description
Makes a quantile-quantile plot of a sample in the input (x)
against the optional input (distname). A 45 degree line is also plotted. The
larger the deviation from the reference line the more likely it is the input
(x) does not come from the distribution (distname).
Inputs:
x = matrix (column vector) in
which the sample data is stored.
distname = string, optional distribution
name to assume as the parent distribution for the sample. Default value is
'normal'. If distname = 'select' or = '', the user is prompted to select one of
the valid distribution types to use. If distname = 'auto' or 'automatic' then
the best fitting distribution is used as determined by DISTFIT.
translate = scalar, axis translation.
Outputs:
The return value is a structure with the following
fields:
q = quantile
of the named distribution.
u = values
at which the quantiles were evaluated.
Options
plots: [ 'none' | {'final'} ] Governs plotting. If
'none', no plot is created and the function simply returns the fit (see
outputs).
histogram: [
{'off'} | 'on' ] Governs the plotting of a histogram of the measured and
reference distribution below the main QQ plot.
translate: [
0 ] translate the x axis by this offset {default = 0}.
varname: [ '' ] label name to use on x-axis and title. Default
is empty which uses the actual input variable name.
color: [ 'b' ] symbol color to use for the plot(s).
Examples
vals = plotqq(x)
vals = plotqq(x,'normal')
vals = plotqq(x,'beta')
See Also
