### Propability plots

Posted:

**Thu Nov 20, 2003 8:53 am**I need propability plots to show a normal distribution or a weibull distribution and so on.

Greetings Heinz

Greetings Heinz

Steema Software - Customer Support Forums

https://www.steema.com/support/

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Posted: **Thu Nov 20, 2003 8:53 am**

I need propability plots to show a normal distribution or a weibull distribution and so on.

Greetings Heinz

Greetings Heinz

Posted: **Mon Nov 24, 2003 5:46 pm**

Hi, Heinz.

Using the latest TeeChart version which supports custom axis labels (text and position for individual labels) implementing any non-linear plot should be easy. All you need is transformation for values and labels.

I've implemented it for normal, Weibull and Q-Q plots. I'll prepare an article about this shortly and post it here.

Using the latest TeeChart version which supports custom axis labels (text and position for individual labels) implementing any non-linear plot should be easy. All you need is transformation for values and labels.

I've implemented it for normal, Weibull and Q-Q plots. I'll prepare an article about this shortly and post it here.

Posted: **Tue Oct 19, 2004 6:13 pm**

When is shortly (mentioned in 2003 november ) ?

Posted: **Thu Aug 17, 2006 7:05 pm**

Hi.

Sorry about (long) delay. I've implemented some of the probabilities plots (among other addditional statistical charts) for another statistical library I'm working on. Some images are available at http://www.dewresearch.com/StatsSeriesGallery.html. In case you're interested I can send you full C# sources (for TeeChart .NET).

Sorry about (long) delay. I've implemented some of the probabilities plots (among other addditional statistical charts) for another statistical library I'm working on. Some images are available at http://www.dewresearch.com/StatsSeriesGallery.html. In case you're interested I can send you full C# sources (for TeeChart .NET).

Posted: **Tue Feb 27, 2007 9:00 pm**

I have now implemented probability plots in EpiData using a standard point series of teechart. The sequence is:

http://www.epidata.dk - general download page later or currently: http://www.epidata.dk/testing.php

example:

For a test users can download an application at:1. create a series with cumulative percentages

.. xvalues cumpercentage

2. convert to probabilities, e.g. see

.. xvalues cumprob

Bland M: Introduction to Medical Statistics. Oxford, 2nd ed. p 112.

3. find an inverse normal function for the probabilites

yvalue = inverse normal (cumprob)

(search internet for "normal probability .....source code", you will get several hits., e.g. "normal probability pascal source"

4. create a standard TChart with a pointseries and do a addxy(xvalues yvalue) and you have the normal probability plot

http://www.epidata.dk - general download page later or currently: http://www.epidata.dk/testing.php

example:

Posted: **Mon Oct 01, 2007 1:48 pm**

Marjan,Marjan wrote:Hi.

Sorry about (long) delay. I've implemented some of the probabilities plots (among other addditional statistical charts) for another statistical library I'm working on. Some images are available at http://www.dewresearch.com/StatsSeriesGallery.html. In case you're interested I can send you full C# sources (for TeeChart .NET).

I would be very interested in the QQ-plot code. Would you be able to send me a copy?

Cheers

Francis

Posted: **Tue Oct 02, 2007 11:13 am**

Hi Francis,

Marjan told me that he uses some specialized code to calculate each point Q-Q value so it's a bit difficult to split it into a simple unit. But basically he's using the same approach other customer reported (epidata). He's doing normal probability plot, but if you omit the normalcdf calculation on y values, you'll end up with Q-Q chart.

Marjan told me that he uses some specialized code to calculate each point Q-Q value so it's a bit difficult to split it into a simple unit. But basically he's using the same approach other customer reported (epidata). He's doing normal probability plot, but if you omit the normalcdf calculation on y values, you'll end up with Q-Q chart.