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Glossary
Active Data Set Q-Q-Plot Acknowledgement Disclaimer
Active Data Set
All estimation and visualization procedures use the
active data set. This is the data set most recently
loaded (see Load Data) or generated
by a simulation. One may activate another data set by means of
the Choose Data option
that lists all data sets used during a session.
Q-Q-Plot
Let F[mu,sigma] be dfs with location and scale
parameters mu and sigma. The sample q-quantile is
plotted against the q-quantile of the standard
df F = F[0,1].
If the data are governed by F[mu,sigma], then the
Q-Q-plot is close to a line with slope sigma and
intercept mu (see Statistical Analysis, page 56,
for details). A stronger deviation from a straight line
indicates that the modeling by the location- and scale-parameter
family is not adequate. An additional shape parameter must
first be replaced by an estimate.
More precisely, the ith ordered value x[i:n] is plotted
against the standard quantile function (qf) evaluated
at q(i) = (i-1/3)/(n+1/3). In addition, there is a linear
interpolation of the points (if this is the actual plotting
option).
Acknowledgement
We refer to the Preface of Statistical Analysis
for the names of those who assisted in programming Xtremes 3.1.
Disclaimer
Xtremes Group does not offer any representations or warranties for
Xtremes Group products in respect to their performance or fitness
for a particular purpose. Xtremes Group believes that the information
contained in this manual is correct. However, Xtremes Group reserves
the right to revise the product hereof and make any changes to the contents
without the obligation to notify any user of this revision.
Xtremes Group does not assume the responsibility for the use of
this manual, nor the product described therein.
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