2.22 Weibull Fit with Least Squares Method

Weibull-Fit-Least-Squares

Summary

This Weibull Fit with Least Squares Method app can be used to estimate parameters for Weibull distribution with least squares method. Least squares method is more accurate than maximum likelihood estimation method for small samples when there are few censoring samples.

Tutorial

1. With a worksheet window activated, select Data: Import Form File: Single ASCII in the menu to import the sample file <Origin Program Folder>\Samples\Statistics\weibull fit.dat with the default import settings.
2. Click on Weibull Fit with Least Squares Method icon from the Apps panel.
3. In the pop-up dialog, set Column A as Time Range, Column B as Censor Range. Check Covariance Matrix check box to output covariance matrix of parameters. Click OK button.

   

4. Get the report sheet WBLLS1.

   

5. Double-click on the Probability Plot in the report sheet. Then click on the Add Percentile Lines button at the bottom right of the graph to open the Add Percentile Lines dialog. Specify percentile lines by Percent (%) . Set Percent Value (%) to 30

   

6. Click OK button to calculate the time or percent for the given value in the dialog. Two drop lines will be added to the graph.