Fitting Continuous Distributions

Select the Continuous Distributions option button and any continuous distribution type from the Distribution Fitting Startup Panel, and click OK to display the Fitting Continuous Distributions dialog box, which contains three tabs: Quick, Parameters, and Options. Note that alternative fitting options are available using Survival Analysis. Survival Analysis is particularly useful for fitting the Weibull and Gompertz distributions, which are widely used for modeling survival or failure times, and are also specifically "equipped" to handle censored data, that is, data that are incomplete. See also, Fitting Discrete Distributions.

Distribution. The Distribution box is available only after a variable has been selected. Use the Distribution box to select the continuous distribution type you want to fit. Note that the distribution selection is automatically set to match the continuous distribution type you selected in the Distribution Fitting Startup Panel, but you can change the distribution here if you want.

Variable. Click the Variable button to display a standard variable selection dialog box, in which you select the variable that will be used in the analysis.

Summary. Click the Summary button to display either a standard variable selection dialog box, or the analysis of the observed and expected distribution (if a variable has already been selected).

Cancel. Click the Cancel button to return to the Distribution Fitting Startup Panel.

Options. Click the Options button to display the Options menu.

By Group.  Click the By Group button to display the By Group specification dialog box.

Select Cases. Click the Select Cases button to display the Analysis/Graph Case Selection Conditions dialog box, which contains options to create conditions for which cases will be included (or excluded) in the current analysis. More information is available in the case selection conditions overview, syntax summary, and dialog box description.

W. Click the W (Weight) button to display the Analysis/Graph Case Weights dialog box, which contains options to adjust the contribution of individual cases to the outcome of the current analysis by "weighting" those cases in proportion to the values of a selected variable.