WeibullDataSet Class

Provides Provides the functionality of a Weibull++ standard folio, including entering data in a data set, specifying analysis settings and fitting a distribution to the data set.

Constructors

• WeibullDataSet() Initializes a new instance of the WeibullDataSet class with a system-supplied data set name.
• WeibullDataSet( ByVal Name As String ) Initializes a new instance of the WeibullDataSet class with a specified data set name.

Parameters

Name: The name of the data set.

Methods

Use these methods to enter data points into a data sheet and analyze them. The settings for the analysis are specified with this class's properties.

Add/Remove Data

• AddFailure Adds failure times to the data set, using the specified time and number of failures at that time.
• AddSuspension Adds suspensions to the data set, using the specified time and number of suspensions at that time.
• AddFailureInterval Adds interval censored failures to the data set, using the specified start/end times and number of failures that occurred within the interval.
• AddSuspensionInterval Adds interval censored suspensions to the data set, using the specified start/end times and number of suspensions for that interval.
• AddFreeForm Adds a free-form data point to the data set, using the specified time and percentage values.
• ClearDataSet Clears all data in the data set and removes the fitted model, if any.

Calculate

• Calculate Fits the distribution to the current data set using the settings specified in the AnalysisSettings property.
• CalculateBestFit Automatically finds the best fitting distribution and fits that distribution to the current data set using the settings specified in the BestFitSettings property.

Properties

Use these properties to specify analysis settings and view analysis results, as well as view or edit properties of the data set.

Analysis Settings

• AnalysisSettings Sets the control panel settings for use with the Calculate method.
• BestFitSettings Sets the Distribution Wizard and control panel settings for use with the CalculateBestFit method.
• GeneralSettings Sets some of the Application Setup calculation options that can apply to both the Calculate and CalculateBestFit methods.

Analysis Results

• FittedModel Gets the fitted model from the life data analysis. This property is cleared if the analysis could not be completed.
• AnalysisResults Gets the correlation coefficient, likelihood value and percent non-zero values that were estimated from the analysis, if applicable.

Data Set Properties

• DatasetName Gets or sets the name of the data set, which will be displayed on any plot you create.
• FailureCount Gets the total number of failures in the data set.
• SuspensionCount Gets the total number of suspensions in the data set.

Related Classes

• Events all the event handlers that can be called by WeibullDataSet. To use events, you must inherit the class, override its methods and assign its instance to the Events property of a WeibullDataSet. WeibullEvents inheritance is not available in VB6/VBA.
  

Usage Example

This example illustrates how to use some of the elements in the WeibullDataSet class.

Declare the WeibullDataSet. See New WeibullDataSet for additional details.

       Dim WDS as New WeibullDataSet

Add values to the raw data. See AddFailure for additional details.

       WDS.AddFailure(1, 1)
       WDS.AddFailure(2, 1)
       WDS.AddFailure(3, 1)

Add values to the raw data. See AddSuspension for additional details.

       WDS.AddSuspension(1, 1)
       WDS.AddSuspension(2, 1)
       WDS.AddSuspension(3, 1)

Calculate the WeibullDataSet. See Calculate for additional details.

       WDS.Calculate

Get the number of failures. In this example, NumberOfFailures will be 3. See FailureCount for additional details.

       Dim NumberOfFailures as Integer
       NumberOfFailures = WDS.FailureCount

Calculate the Fitted Model using the raw data. See CalculateBestFit for additional details.

       WDS.CalculateBestFit

Use the Fitted Model using the raw data. See FittedModel for additional details.

       Dim WDSFittedModel as cModel
       WDSFittedModel = WDS.FittedModel

Use ClearDataSet to clear data and fitted model. See ClearDataSet for additional details.

       WDS.ClearDataSet

Get the number of failures. In this example, NumberOfFailures will be 0. See FailureCount for additional details.

       Dim NumberOfFailures as Integer
       NumberOfFailures = WDS.FailureCount