FDIST & FINV calculation formula

[luinox86]

Dear All,

I am a new member here so I am not sure I am posting in the right place or not.

Anyway, I am actually a programmer, we need to get the values that FDIST and FINV produce, directly into our program because of the access-delay that happens in connecting to excel.

We are writing code in a project in Visual Basic 6.

I will appreciate any help to know what is happening inside FDIST and FINV functions of Microsoft Excel 2007; the formula, and etc.


Thanks.

[MarvinP]

Hi luinox86,
Here are a few links to discribe the F Distribution Probability function:
http://office.microsoft.com/en-us/ex...005209087.aspx
http://en.wikipedia.org/wiki/F-distribution
http://www.itl.nist.gov/div898/handb...n3/eda3665.htm

Good luck.

[MarvinP]

You can do a WorksheetFunction.FDist from Excel VBA. I don't know if you can get it from VB6.

[luinox86]

Dear MarvinP,

Thank you for your respond. The links were helpful, specially the Wikipedia one. You know, the problem is that I am not really good in mathematics. I was looking for a straight forward formula that I can put my numbers in. I will appreciate it if you can help me to simplify the formulas.

My goal is particulary to get the all variables(results) of the 'F-Test two samples for variances' function in Excel. I know how to use this function, lets say I have two sets of data:

Set1: 11, 2, 16, 12, 7, 18, 15, 22, 14, 19
Set2: 15, 8, 23, 12, 21, 13, 23, 10, 15, 16

After performing the 'F-Test two samples for variances' function, i get the result table.

The table consists of 7 variables presented as results. What I need to do is to find the mathematic formula for all of them, so I can convert them into visual basic.

I have already found the first 5; the last 2 I couldn't find so far and seems like these are not very simple!

I have attached the result I have taken by the function in Excel 2007. Those values with the tag 'DONE' in their next cell, mean that I have already found the formula for them; while the bold ones still need to be discovered.

If there is any code shown in excel for this calculation using VBA I can convert it easily into VB6. Can you tell me how can I access that code?

Again, i appreciate your help if you can simplify the formulas for FDIST and FINV functions or show me the VBA code.

[MarvinP]

I don't know VB6 but was hoping you could do an "Application.WorksheetFunction.FDist( )" to the Excel application on your machine. This way you are using the .dll files from Excel and wouldn simply need to pass the correct arguments to the call.

The point of showing you the links, was to show you it isn't a simple formula to resolve. This is why using the call to Excel makes a lot more sense.

[luinox86]

Dear MarvinP,

Yes, it is complicated and I hope someone can explain it to me.

I can not use of the dll function call because we need the program to run in real-time mode and there is a slight delay in accessing DLLs from excel.

Thousands of data need to be calculated one by one and taking them from Excel dlls simply does not work; it should be a function written directly inside vb6.


Thanks anyway.
Any future help is also appreciated in advance!