How do I calculate the 0.00135 quantile of a given distribution?When calculating process capability, if the data does not follow a normal distribution, it is necessary to find the X0.00135 quantile of another distribution (such as the Weibull distribution).
How can I calculate the 0.00135 quantile of the distribution shown in the image below using JMP?
Quality and Process Engineering
Re: 请问如何计算某个分布的X0.00135分位数?Hi @Xinghua ,
There are a couple different ways you can do this.
From the Distribution platform, you can click the red hot-button next to the name of whatever you're analyzing (Purity), select Display Options and Custom Quantiles.
This will give you a popup window that allows you to enter whatever custom quantiles you want.
Or, if you have JMP v19, once you've fitted the data to get your continuous distribution, you can click the red hot-button next to Fitted Weibull Distribution, and select Fitted Quantiles, which gives you a similar popup window.
Hope this helps!,
DS
Re: 请问如何计算某个分布的X0.00135分位数?Hi @Xinghua : You can also use the quantile profiler under the Fitted Weibull Distribution output if you want the quantile based on the fitted Weibull distribution.
Re: 请问如何计算某个分布的X0.00135分位数?Thank you very much.
Re: How do I calculate the 0.00135 quantile of a given distribution?I just tried it out, and the quantiles provided by JMP, as well as the custom quantiles, are based on the data (arranged from smallest to largest), not on the distribution the data follows. What I need are the quantiles of the distribution (calculated using the area of the distribution).
As shown in the figure below, the red area on the left side of X=99.73 accounts for 5% of the total area.
Re: 请问如何计算某个分布的X0.00135分位数?Hi @Xinghua : As I indicated in my previous post, you can use the quantile profiler under the Fitted Weibull Distribution output if you want the quantile based on the fitted Weibull distribution.
Edit: Just click on the red triangle next to "Fitted Weibull Distribution" and choose Profilers/Quantile Profiler. Then in the Quantile Profiler, input 0.00135 on the X-axis labeled Probability. The quantile will then be displayed on the Y-axis.
Re: How do I calculate the 0.00135 quantile of a given distribution?You may have actually solved my problem—finding a quantile of a distribution (not just the quantiles of the data). Thank you so much!
