Author 
Topic 

AKazak
Russia
706 Posts 
Posted  12/30/2021 : 10:44:29 AM

OriginPro 2022 (64bit) SR1 9.9.0.225 Windows 7 Pro SP1 x64
Greetings!
I enjoy using the Distribution function of a Histogram plot.
Is there a way to show the Distribution equation or its parameters on the graph?
Thank you.
 Andrey 

easwar
USA
1957 Posts 
Posted  12/30/2021 : 11:38:46 AM

Hi Andrey,
Thank you for the post, I have added a request for this for our next version (internal jira ID: ORG24709)
Easwar OriginLab



AKazak
Russia
706 Posts 
Posted  12/30/2021 : 11:44:54 AM

quote: Originally posted by easwar
Hi Andrey,
Thank you for the post, I have added a request for this for our next version (internal jira ID: ORG24709)
Easwar OriginLab
I would be happy to test it.
By the way, what is the principal barrier to using Quick Fit Gadget in a Histogram plot window?
 Andrey 


easwar
USA
1957 Posts 
Posted  12/30/2021 : 1:30:04 PM

Hi Andrey,
We have never supported fitting directly on the histogram plot due to some internal reasons. So we recommend creating the bin worksheet and then fitting that data.
BTW fitting a histogram/frequency count output can result in inconsistent fit parameters, as the parameter values from the fit may be sensitive to the bin size. A better approach is to perform Distribution Fit to the raw data itself, using the Statistics>Descriptive Statistics>Distribution Fit tool. Granted, that does not have ALL of the distributions that are available for overlay in the histogram plot.
Easwar 


AKazak
Russia
706 Posts 
Posted  12/30/2021 : 1:47:18 PM

quote: Originally posted by easwar
Hi Andrey,
We have never supported fitting directly on the histogram plot due to some internal reasons. So we recommend creating the bin worksheet and then fitting that data.
BTW fitting a histogram/frequency count output can result in inconsistent fit parameters, as the parameter values from the fit may be sensitive to the bin size. A better approach is to perform Distribution Fit to the raw data itself, using the Statistics>Descriptive Statistics>Distribution Fit tool. Granted, that does not have ALL of the distributions that are available for overlay in the histogram plot.
Easwar
Thank you for the suggestion. However, I want to benefit from interactive data selection and fit results' estimation on the fly.
Can you elaborate on "fitting a histogram/frequency count output can result in inconsistent fit parameters, as the parameter values from the fit may be sensitive to the bin size", please?
 Andrey 


easwar
USA
1957 Posts 
Posted  12/30/2021 : 2:23:46 PM

quote:
Can you elaborate on "fitting a histogram/frequency count output can result in inconsistent fit parameters, as the parameter values from the fit may be sensitive to the bin size", please?  Andrey
Hi Andrey,
For example, I generated some data in col A of a blank worksheet using script window: col(1)=nint(100+20*normal(1000));
This should then be a normal distribution with mean of 100 and sigma of 20.
If I then bin this data using the Frequency Count tool (same as what histogram plot and bin worksheet does) with two different bin widths of 5 and 20, and then plot the counts and add the quick fit gadget, you can see the parameter values are different. OF course I chose very different bin widths just to illustrate the point.
Now if I use the raw data itself and perform a distribution fit, I get the result shown in the book at the bottom of the image.
Easwar 



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