Weibull++ Weibull Degradation Plot ptProbability: Difference between revisions

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When the parameters have been calculated using rank regression analysis, the regression line is fitted to the data points on the plot in order to obtain the distribution parameters. Therefore, the plot can also be used to compare how different distributions fit a particular data set. The closer the regression line tracks the points on the plots, the better the fit.
When the parameters have been calculated using rank regression analysis, the regression line is fitted to the data points on the plot in order to obtain the distribution parameters. Therefore, the plot can also be used to compare how different distributions fit a particular data set. The closer the regression line tracks the points on the plots, the better the fit.


The next figures show the rank regression analysis of single data set using a Weibull distribution and a lognormal distribution. As you can see, the probability plot shows that the Weibull distribution presents the better fit to this particular data set
Example figure:


[[Image:probabilityplotweibull.png|left|200px]]
[[Image:Probabilitygumbel.gif|left|200px]]
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|valign="middle" | [http://www.reliawiki.com/index.php/Weibull%2B%2B_Plots Weibull++ Plots]
|valign="middle" | [http://www.reliawiki.com/index.php/Weibull%2B%2B_Plots Weibull++ Plots]

Revision as of 16:47, 9 February 2012

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Degradation Plot Probability - Weibull
Weibull++

Probability

The Probability plot shows the trend in the probability of failure over time. The plotting positions of the data points are determined by the failure/suspension times in the data set (x-axis) and their corresponding unreliability estimates (y-axis).

When the parameters have been calculated using rank regression analysis, the regression line is fitted to the data points on the plot in order to obtain the distribution parameters. Therefore, the plot can also be used to compare how different distributions fit a particular data set. The closer the regression line tracks the points on the plots, the better the fit.

Example figure:

Probabilitygumbel.gif
Weibull++ Plots



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