Variables << >>
If more than one variable is selected for the analysis, you can switch between them via the
Variables << and >> buttons (or use the adjacent drop-down menu).
Distribution << >>
If more than one distribution is specified for the selected variable, you can switch between them via the
Distribution << and >> buttons (or use the adjacent drop-down menu).
Summary statistics
Click the
Summary statistics button to create a spreadsheet that contains descriptive statistics (e.g. mean, standard deviation etc.) for the currently selected variable.
Summary graph
Click the
Summary graph button to produce a compound graph for the selected variable consisting of a histogram, normal probability plot, box plot, and descriptive statistics.
Distribution summary statistics
Click the
Distribution summary statistics button to produce the parameter estimation and goodness of fit tests results for each selected distribution for the currently selected variable.
Empirical CDF plot
Click the
Empirical CDF plot button to produce a graph that consists of the empirical CDF, the theoretical CDF of the currently selected distribution, and 95% confidence bands for the sample CDF.
Histogram with fit
Click the
Histogram with fit button to produce a histogram with the theoretical density function of the currently selected distribution superimposed over the observed frequencies.
Cumulative histogram
Click the
Cumulative histogram button to produce a cumulative histogram with the theoretical cumulative function of the currently selected distribution superimposed over the observed cumulative frequencies.
P-P plot
Click the
P-P plot button to produce a P-P plot. In the P-P (probability-probability) plot, the observed cumulative distribution function is plotted against the theoretical cumulative distribution function for the same values. If the selected distribution provides a good fit to the observed data, then all data points will fall onto the diagonal in this plot. See also, Conceptual Overviews - Probability-Probability Plots.
Q-Q plot
Click the
Q-Q plot button to produce a Q-Q plot. To produce a Q-Q plot, Statistica will first sort the N observed data points into ascending order, so that:
x(1) <=.x(2) <= ... <=.x(n)
These observed values are plotted against one axis of the graph; on the other axis the plot will show:
F-1 ((i-radj )/(n+nadj ))
where
i is the rank of the respective observation,
radj and
nadj are adjustment factors (<= 0.5) and F-1 denotes the inverse of the probability integral for the selected standardized distribution. See also, Conceptual Overviews - Quantile-Quantile Plots.
Box plot
Click the
Box plot button to display a box and whisker plot for the selected variable. The box and whisker plot will summarize each variable by three components:
A central circle to indicate the mean; a box to indicate the mean plus/minus the standard deviation; whiskers around the box to indicate the mean plus/minus 1.96*standard deviation (hence, if your data follows the normal distribution, 95% of your data should fall within the whiskers).
The following options are available regardless of which tab is selected.
Run simulation
Click the
Run simulation button to display the
Simulation Methods dialog where you can simulate random data from the best fitting distributions as specified on the
Save Fit tab. Simulated data can be generated independently for each column, or you can select to preserve the correlation structure between the variables.
Cancel
Click the
Cancel button to close the dialog and return to the
Fit Distributions dialog without performing an analysis.
Options
Click the
Options button to display the Options menu.