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mmashaie

Stat::Fit to Simio distributions

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I understand that Stat::Fit can export distributions to Simio format. Is this possible for Stat::Fit version 2? If not, is there a "translation" available, similar to the attachment that shows BestFit to Simio?


Thanks.

Maryam

30-04-2014 1-17-06 PM.pdf

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Yes, StatFit Vsn 2 includes the simio support. When you export the fitted distribution, simply select Simio from the list. It will copy the appropriate distribution ino the paste buffer using correct Simio syntax. Then you can switch to Simio and paste (Ctrl-V) it into the expression field.StatFitExport.JPG.771149e599f98f2e3123db9f5eb2c846.JPG

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Very helpful, thanks very much.


If I have been given a Pearson5 distribution from Stat::Fit as Pearson5(5,3.78,90.1), but knowing that there is no Pearson5 in Simio and that there is PearsonVI (Pearson6 I assume), can I "translate" Pearson5 with the given parameter values to Pearson6?


I am currently running 5.94.10525 (32 bit); I will upgrade to latest version once I know my model is working.


Thanks.

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I don't know the details about the various Pearson distributions, but I would think that if it is possible to convert between them that when you select Simio it would automatically generate an expression using PearsonVI.

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Does an EasyFit to Simio translation exist? From what I know, EasyFit is working on an export to Simio distributions, but in the meantime I was hoping to find some documentation.


Thanks.

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Hi,


I have experimented with several distribution fitting software and although most are good the translation back to Simio remains a problem. I know stat:fit provides this capability, but I feel there are better programs out there to fit distributions (easier faster and better).

Is there any translation documentation available to shift from @Risk to Simio?

Otherwise is there a more in depth documentation to simplify the translation?

Lastly does the Simio team plan on improving there distribution fitting interfaces or not?


Regards

Willem

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See this topic: http://www.simio.com/forums/viewtopic.php?f=14&t=919&p=2514


Since there are many good commercial products available, several of which have custom support for Simio, we have no plans to reinvent the wheel by creating our own software equivalent for fitting data.


But Simio has implemented a different technology which is actually a better solution than fitting data for many, but certainly not all, applications. Fitting a distribution is essentially constructing an equation that is an approximation of the real data that one might expect to encounter. While in some cases this artificial representation is appropriate, in many cases it actually introduces additional error by creating data which might never occur. (Reference recent work by Dr. Barry Nelson of Northwestern University.)


As an alternative to fitting and equation to data, Simio allows the option of reading this raw data into a data table and then creating an Input Parameter to directly sample from this data. This has the advantage of not creating artificial data or approximating an equation. And just like with fitting a distribution, the more data you have, the more accurate this approach can be.

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Thanks David,


The sampling from a table approach, was a very good addition!


I have created a macro to convert from @Risk distributions to Simio. I have asked @Risk to introduce the conversions (Don't think that they will). Otherwise a standard set of conversion would be useful, I will start a new topic under shared items for the conversions of distributions sharing the macro.


See: http://www.simio.com/forums/viewtopic.php?f=36&p=6703#p6703


Regards,

Willem

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