topic Re: Probability plot for log-normal distribution fitting in Discussions
https://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/272630#M53024
Hi gzmorgan0,<BR />I agree, making the log transformation is a great way to get the intervals on the plot too. I did this before but was also wondering about getting a plot for the log fit. The PP/QQ do a good job.<BR />Thanks for the help.Sun, 14 Jun 2020 23:31:16 GMTmtrain2020-06-14T23:31:16ZProbability plot for log-normal distribution fitting
https://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/271704#M52889
<P>Hi,</P><P>Is there an option to view the probability plot when making a log-normal fit with a distribution analysis?</P><P>Thanks</P>Wed, 10 Jun 2020 02:30:29 GMThttps://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/271704#M52889mtrain2020-06-10T02:30:29ZRe: Probability plot for log-normal distribution fitting
https://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/271727#M52894
<P>Hi,</P>
<P> </P>
<P>From the red hotspot of beside the name of your column in the Distribution platform choose "Continuous Fit -->Fit lognormal." Then, from red hotspot beside "Fitted Lognormal Distribution," choose "Diagnostic Plots." You then have the option of fitting the P-P and/or Q-Q plots. Is that what you're looking for? </P>Wed, 10 Jun 2020 08:53:04 GMThttps://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/271727#M52894HadleyMyers2020-06-10T08:53:04ZRe: Probability plot for log-normal distribution fitting
https://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/271993#M52911
<P><LI-USER uid="16716"></LI-USER>,</P>
<P><LI-USER uid="7531"></LI-USER> provided you with a solution. However, if your lognormal distribution has a large mean and/or variance, the scaling on the QQ plot usually does not have the familiar custom probability plot that scales the Y axes like custom probability paper (yes I am showing my age, things we used pre graphical calculator/computer days).</P>
<P> </P>
<P>I suggest you right click on the column of data you're fitting, select <STRONG>Transform</STRONG> and use <STRONG>Log</STRONG>, then <STRONG>Continuous Fit > Fit Normal</STRONG>.</P>
<P> </P>
<P>Below is a screenshot of <STRONG> Analyze > Distribution > Continuous Fit > Fit Normal</STRONG> of 100 random lognormal(4,2) values transformed with Log. The table with script is attached. </P>
<P> </P>
<P>Another suggestsion is to use the QQ plot that Hadley suggested and click on the Y axis of he QQ plot and change Linear to Log. </P>
<P> </P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="image.png" style="width: 999px;"><img src="https://community.jmp.com/t5/image/serverpage/image-id/24498iC56BE1A935C0E4C2/image-size/large?v=1.0&px=999" role="button" title="image.png" alt="image.png" /></span></P>
<P> </P>
<P> </P>
<P> </P>Wed, 10 Jun 2020 21:18:11 GMThttps://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/271993#M52911gzmorgan02020-06-10T21:18:11ZRe: Probability plot for log-normal distribution fitting
https://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/272629#M53023
Hi Hadley,<BR />That is what I was looking for but without the confidence interval. But not a big deal.<BR />Thanks for showing me around.Sun, 14 Jun 2020 23:26:40 GMThttps://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/272629#M53023mtrain2020-06-14T23:26:40ZRe: Probability plot for log-normal distribution fitting
https://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/272630#M53024
Hi gzmorgan0,<BR />I agree, making the log transformation is a great way to get the intervals on the plot too. I did this before but was also wondering about getting a plot for the log fit. The PP/QQ do a good job.<BR />Thanks for the help.Sun, 14 Jun 2020 23:31:16 GMThttps://community.jmp.com/t5/Discussions/Probability-plot-for-log-normal-distribution-fitting/m-p/272630#M53024mtrain2020-06-14T23:31:16Z