WeibullDataSet.CalculateBestFit: Difference between revisions

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{{Template:APIClass|WeibullDataSet Class|WeibullDataSet}}
{{Template:API}}{{Template:APIBreadcrumb|.[[WeibullDataSet Class|WeibullDataSet]]}}
{{Template:WeibullDataSet.CalculateBestFit.Cmt}}


This is equivalent to clicking the '''Implement''' button in the Distribution Wizard.
 
<onlyinclude>Performs goodness of fit tests to find the distribution that best fits the data set. Returns a message box that shows the estimated parameters of the distribution that best fits the data. (Similar to the Distribution Wizard feature in Weibull++). Use the <code>BestFitSettings</code> property of the class to specify the criteria for evaluating the fit. </onlyinclude>
 
In addition, the method automatically creates a retrievable [[CModel Class|cModel]] object that represents the fitted model from the life data analysis.  


== Syntax  ==
== Syntax  ==
*CalculateBestFit()
'''.CalculateBestFit


== Usage Example ==
== Example ==
'''VBA'''
{{APIComment|'Declare a new WeibullDataSet object.}}
  {{APIPrefix|Dim}} WDS {{APIPrefix|As New}} WeibullDataSet
{{APIComment|'Add failure times to the data set.}}
  {{APIPrefix|Call}} WDS.AddFailure(100, 1)
  {{APIPrefix|Call}} WDS.AddFailure(120, 1)
  {{APIPrefix|Call}} WDS.AddFailure(130, 1) 
 
{{APIComment|'Consider the normal, lognormal and 2-parameter Weibull distributions in the evaluation.}}
  WDS.BestFitSettings.AllowExponential1 = False
  WDS.BestFitSettings.AllowExponential2 = False
  WDS.BestFitSettings.AllowNormal = True
  WDS.BestFitSettings.AllowLognormal = True
  WDS.BestFitSettings.AllowWeibull2 = True
  WDS.BestFitSettings.AllowWeibull3 = False
  WDS.BestFitSettings.AllowGamma = False
  WDS.BestFitSettings.AllowGenGamma = False
  WDS.BestFitSettings.AllowLogistic = False
  WDS.BestFitSettings.AllowLoglogistic = False
  WDS.BestFitSettings.AllowGumbel = False
 
{{APIComment|'Perform the goodness of fit tests.}}
  {{APIPrefix|Call}} WDS.CalculateBestFit()
 
{{APIComment|'Retrieve the fitted life distribution model.}}
  {{APIPrefix|Dim}} model {{APIPrefix|As}} cModel
  {{APIPrefix|Set}} model = WDS.FittedModel
{{APIComment|'Using the model, calculate the reliability at 100 hrs and display the result.}}
  {{APIPrefix|Dim}} r {{APIPrefix|As}} Double
  r = model.reliability(100)
  MsgBox({{APIString|"Reliability at 100 hrs: "}} & r)


  {{APIComment|'Declare a new WeibullDataSet object. See [[WeibullDataSet Class|WeibullDataSet]].}}
'''VB.NET'''
  Dim WDS As New WeibullDataSet("AddFailure_Example")
  {{APIComment|'Declare a new WeibullDataSet object.}}  
  {{APIPrefix|Dim}} WDS {{APIPrefix|As New}} WeibullDataSet
   
   
  {{APIComment|'Add failure times to the data set.}}
  {{APIComment|'Add failure times to the data set.}}
  WDS.AddFailure(100, 1)
  WDS.AddFailure(100, 1)
  WDS.AddFailure(120, 1)
  WDS.AddFailure(120, 1)
  WDS.AddFailure(130, 1)   
  WDS.AddFailure(130, 1)   
    
    
  {{APIComment|'Specify that the normal, lognormal and 2-parameter Weibull}}
  {{APIComment|'Consider the normal, lognormal and 2-parameter Weibull distributions in the evaluation.}}
{{APIComment|'distributions will be considered.}}
  WDS.BestFitSettings.AllowExponential1 = False
  WDS.BestFitSettings.AllowExponential1 = False
  WDS.BestFitSettings.AllowExponential2 = False
  WDS.BestFitSettings.AllowExponential2 = False
  WDS.BestFitSettings.AllowNormal = True
  WDS.BestFitSettings.AllowNormal = True
  WDS.BestFitSettings.AllowLognormal = True
  WDS.BestFitSettings.AllowLognormal = True
  WDS.BestFitSettings.AllowWeibull2 = True
  WDS.BestFitSettings.AllowWeibull2 = True
  WDS.BestFitSettings.AllowWeibull3 = False
  WDS.BestFitSettings.AllowWeibull3 = False
  WDS.BestFitSettings.AllowGamma = False
  WDS.BestFitSettings.AllowGamma = False
  WDS.BestFitSettings.AllowGenGamma = False
  WDS.BestFitSettings.AllowGenGamma = False
  WDS.BestFitSettings.AllowLogistic = False
  WDS.BestFitSettings.AllowLogistic = False
  WDS.BestFitSettings.AllowLoglogistic = False
  WDS.BestFitSettings.AllowLoglogistic = False
  WDS.BestFitSettings.AllowGumbel = False
  WDS.BestFitSettings.AllowGumbel = False
    
    
  {{APIComment|'Fit the data to the life distribution that is estimated to have the best fit.}}
  {{APIComment|'Perform the goodness of fit tests.}}
  WDS.CalculateBestFit()
  WDS.CalculateBestFit()
    
    
  {{APIComment|'Retrieve the fitted life distribution model. See [[cModel Class|cModel]].}}
  {{APIComment|'Retrieve the fitted life distribution model.}}
  Dim model As cModel
  {{APIPrefix|Dim}} model {{APIPrefix|As}} cModel
  model = WDS.FittedModel
  model = WDS.FittedModel
{{APIComment|'Using the model, calculate the reliability at 100 hrs and display the result.}}
  {{APIPrefix|Dim}} r {{APIPrefix|As}} Double
  r = model.reliability(100)
  MsgBox({{APIString|"Reliability at 100 hrs: "}} & r)

Revision as of 22:38, 30 March 2016

APIWiki.png


Member of: SynthesisAPI.WeibullDataSet


Performs goodness of fit tests to find the distribution that best fits the data set. Returns a message box that shows the estimated parameters of the distribution that best fits the data. (Similar to the Distribution Wizard feature in Weibull++). Use the BestFitSettings property of the class to specify the criteria for evaluating the fit.

In addition, the method automatically creates a retrievable cModel object that represents the fitted model from the life data analysis.

Syntax

.CalculateBestFit

Example

VBA

 'Declare a new WeibullDataSet object.  
  Dim WDS As New WeibullDataSet

 'Add failure times to the data set. 
  Call WDS.AddFailure(100, 1)
  Call WDS.AddFailure(120, 1)
  Call WDS.AddFailure(130, 1)  
 
 'Consider the normal, lognormal and 2-parameter Weibull distributions in the evaluation. 
  WDS.BestFitSettings.AllowExponential1 = False
  WDS.BestFitSettings.AllowExponential2 = False
  WDS.BestFitSettings.AllowNormal = True
  WDS.BestFitSettings.AllowLognormal = True
  WDS.BestFitSettings.AllowWeibull2 = True
  WDS.BestFitSettings.AllowWeibull3 = False
  WDS.BestFitSettings.AllowGamma = False
  WDS.BestFitSettings.AllowGenGamma = False
  WDS.BestFitSettings.AllowLogistic = False
  WDS.BestFitSettings.AllowLoglogistic = False
  WDS.BestFitSettings.AllowGumbel = False
 
 'Perform the goodness of fit tests. 
  Call WDS.CalculateBestFit()
 
 'Retrieve the fitted life distribution model. 
  Dim model As cModel
  Set model = WDS.FittedModel

 'Using the model, calculate the reliability at 100 hrs and display the result. 
  Dim r As Double
  r = model.reliability(100)
  MsgBox("Reliability at 100 hrs: " & r)

VB.NET

 'Declare a new WeibullDataSet object.  
  Dim WDS As New WeibullDataSet

 'Add failure times to the data set. 
  WDS.AddFailure(100, 1)
  WDS.AddFailure(120, 1)
  WDS.AddFailure(130, 1)  
 
 'Consider the normal, lognormal and 2-parameter Weibull distributions in the evaluation. 
  WDS.BestFitSettings.AllowExponential1 = False
  WDS.BestFitSettings.AllowExponential2 = False
  WDS.BestFitSettings.AllowNormal = True
  WDS.BestFitSettings.AllowLognormal = True
  WDS.BestFitSettings.AllowWeibull2 = True
  WDS.BestFitSettings.AllowWeibull3 = False
  WDS.BestFitSettings.AllowGamma = False
  WDS.BestFitSettings.AllowGenGamma = False
  WDS.BestFitSettings.AllowLogistic = False
  WDS.BestFitSettings.AllowLoglogistic = False
  WDS.BestFitSettings.AllowGumbel = False
 
 'Perform the goodness of fit tests. 
  WDS.CalculateBestFit()
 
 'Retrieve the fitted life distribution model. 
  Dim model As cModel
  model = WDS.FittedModel

 'Using the model, calculate the reliability at 100 hrs and display the result. 
  Dim r As Double
  r = model.reliability(100)
  MsgBox("Reliability at 100 hrs: " & r)
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