WeibullDataSet.CalculateBestFit: Difference between revisions

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<onlyinclude>Performs goodness of fit tests to find the distribution that best fits the data set (similar to the Distribution Wizard feature in Weibull++). Returns a message box that shows the estimated parameters of the distribution that best fits the data and creates a retrievable [[CModel Class|cModel]] object that represents the fitted model from the life data analysis.</onlyinclude>  
<onlyinclude>Determines which of the selected life distributions best fits the data set (similar to the Distribution Wizard feature in Weibull++) and creates a [[CModel Class|cModel]] object that represents the fitted model of the recommended distribution.</onlyinclude>  


Use the <code>BestFitSettings</code> property of the class to specify the criteria for evaluating the fit.  
 
'''Remarks''': To specify the distributions, parameter estimation method and other criteria for evaluating the fit, use the <code>BestFitSettings</code> property of the object. To return the <code>cModel</code> object that is produced, use the <code>FittedModel</code> property of the object.


== Syntax  ==
== Syntax  ==
Line 33: Line 34:
   WDS.BestFitSettings.AllowGumbel = False
   WDS.BestFitSettings.AllowGumbel = False
    
    
  {{APIComment|'Perform the goodness of fit tests.}}
  {{APIComment|'Use the MLE parameter estimation method.}}
  WDS.BestFitSettings.Analysis = WeibullSolverMethod_MLE
{{APIComment|'Determine which distribution best fits the data set, based on the MLE method.}}
   {{APIPrefix|Call}} WDS.CalculateBestFit()
   {{APIPrefix|Call}} WDS.CalculateBestFit()
 
    
{{APIComment|'Retrieve the fitted life distribution model.}}
  {{APIComment|'Calculate the reliability at 100 hrs and display the result.}}
   {{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
   {{APIPrefix|Dim}} r {{APIPrefix|As}} Double
   r = model.reliability(100)
   r = WDS.FittedModel.Reliability(100)
   MsgBox({{APIString|"Reliability at 100 hrs: "}} & r)
   MsgBox({{APIString|"Reliability at 100 hrs: "}} & r)


Line 67: Line 67:
   WDS.BestFitSettings.AllowLoglogistic = False
   WDS.BestFitSettings.AllowLoglogistic = False
   WDS.BestFitSettings.AllowGumbel = False
   WDS.BestFitSettings.AllowGumbel = False
{{APIComment|'Use the MLE parameter estimation method.}}
  WDS.BestFitSettings.Analysis = WeibullSolverMethod.MLE
    
    
  {{APIComment|'Perform the goodness of fit tests.}}
  {{APIComment|'Determine which distribution best fits the data set, based on the MLE method.}}
   WDS.CalculateBestFit()
   WDS.CalculateBestFit()
 
    
{{APIComment|'Retrieve the fitted life distribution model.}}
  {{APIComment|'Calculate the reliability at 100 hrs and display the result.}}
  {{APIPrefix|Dim}} model {{APIPrefix|As}} cModel
   model = WDS.FittedModel
  {{APIComment|'Using the model, calculate the reliability at 100 hrs and display the result.}}
   {{APIPrefix|Dim}} r {{APIPrefix|As}} Double
   {{APIPrefix|Dim}} r {{APIPrefix|As}} Double
   r = model.reliability(100)
   r = WDS.FittedModel.Reliability(100)
   MsgBox({{APIString|"Reliability at 100 hrs: "}} & r)
   MsgBox({{APIString|"Reliability at 100 hrs: "}} & r)

Latest revision as of 16:07, 17 August 2016

APIWiki.png


Member of: SynthesisAPI.WeibullDataSet


Determines which of the selected life distributions best fits the data set (similar to the Distribution Wizard feature in Weibull++) and creates a cModel object that represents the fitted model of the recommended distribution.


Remarks: To specify the distributions, parameter estimation method and other criteria for evaluating the fit, use the BestFitSettings property of the object. To return the cModel object that is produced, use the FittedModel property of the object.

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
 
 'Use the MLE parameter estimation method. 
  WDS.BestFitSettings.Analysis = WeibullSolverMethod_MLE

 'Determine which distribution best fits the data set, based on the MLE method. 
  Call WDS.CalculateBestFit()
  
 'Calculate the reliability at 100 hrs and display the result. 
  Dim r As Double
  r = WDS.FittedModel.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

 'Use the MLE parameter estimation method. 
  WDS.BestFitSettings.Analysis = WeibullSolverMethod.MLE
 
 'Determine which distribution best fits the data set, based on the MLE method. 
  WDS.CalculateBestFit()
  
 'Calculate the reliability at 100 hrs and display the result. 
  Dim r As Double
  r = WDS.FittedModel.Reliability(100)
  MsgBox("Reliability at 100 hrs: " & r)