Erlang C formula? 2

[terzaghi]

Hi,

does anyone has a roubust algorithm to calculate the erlang c formula? I found on the Internet a good algorithm for Erlang B formula. The Problem is that, in order to evaluate the result, it is necessary, in practical situation, to calculate numbers such as 200^100 and 200!

thanks to anyone who cal help me!

 

[dyarwood]

Do you have the formula for Erlang C?

It can be found here

http://www.incoming.com/queuetips/pages/200203/qt03140203.aspx?SelectedNode=QueueTips

I think there should be so cancelling down or limits you could use.

 

[terzaghi]

Yes I know the formula. as you cans see it says A^N/N! where A is the erlangs and N is the number of servers. in our problem erlang is a number like 100 and N is a number like 120 so I have to evaluate a number like 100^120/120!

(120! is 120*119*118*....*5*4*3*2*1)

so the problem is that exel cannot avaluatre that number even with double precision. does enyone know a nother formula (or algorithm) to avaluate the same thing without calculating that huge numbers? This is my problem. Thanks a lot.

for Erlang B formula its easy to do.. see this link:

http://mathforum.org/library/drmath/view/61679.html

thanks a lot

 

[strongm]

There's a C version here

http://www.csee.usf.edu/~christen/tools/erlang.c

that you might be able to translate

 

[Molby]

Try this website, you have to resister, but the software looks like it is free to download, and it looks like it's an add on to Excel. I hope that is what you are after.

http://www.math.vu.nl/~obpdss/obpdss.php?action=info&subject=callcenter