# 17.6.3 Weibull Fit

## Introduction

There are three kinds of methods to do survival analysis: a non-parameter method, a semi-parameter method, and a parameter method. Weibull fit is a kind of parameter method to analyze the relationship between the survival function and failure time.

From the table of Analysis of parameter estimates, you can determine the relationship between the survival function and the failure time. The value of the survival function can be obtained from the following equation:

$S(x)=exp(-(\frac{x-location}{Weibull\;Scale})^{Weibull\;Shape}) \,\!,$

In Origin, Weibull fit only discusses scale parameter and shape parameter, and assumes location parameter = 0.

## Handling Missing Values

If there are missing values in the Time/Censor range, the whole case will be excluded in the analysis

## Performing Weibull Fit

To perform a Weibull Fit:

1. Select Statistics: Survival Analysis: Weibull Fit. This menu command opens the weibullfit dialog box.
2. Specify the Input Data, including Time and Censor variables. Optionally, choose to create a Weibull Plot.
3. Upon clicking OK, an analysis report sheet is generated.
 Topics covered in this section: Tutorial