- #1
ktoz
- 171
- 12
Hi
The compound summation formula
[tex]v = \frac{(m + l)!(al + a + cm)}{m!(l + 1)!}[/tex]
listed in the "Solve v = f(x) for x" thread uses factorials and in an effort to extend it to non-integral values of "m" and "l", I stumbled across the gamma function http://en.wikipedia.org/wiki/Gamma_function" . Why was it necessary to create such a complicated function just to extend fatorials to non-integers?
Before looking it up, I took a crack at creating a factorial extension and mine seem much more straightforward. Standard factorials are defined like this.
m! = m(m - 1)(m - 2)(m - 3)...(m - m + 1)
if you start from zero, rather than m, you get the exact same answer but it's much easier to calculate.
1 * 2 * 3 * 4 ... * m
Extending this for non integral factorials seems like it would be as simple as
1a * 2a * 3a * 4a ... *ma
Which can be simplified to
a^m * m!
Here, "a" could be any type of number, positive, negative, real, even complex and it seems to be a simple, logical way to extend factorials, so I'm wondering why the gamma is so complex, incorporating integrals, "e" limits etc... and what benefits that complexity adds to the mix.
The compound summation formula
[tex]v = \frac{(m + l)!(al + a + cm)}{m!(l + 1)!}[/tex]
listed in the "Solve v = f(x) for x" thread uses factorials and in an effort to extend it to non-integral values of "m" and "l", I stumbled across the gamma function http://en.wikipedia.org/wiki/Gamma_function" . Why was it necessary to create such a complicated function just to extend fatorials to non-integers?
Before looking it up, I took a crack at creating a factorial extension and mine seem much more straightforward. Standard factorials are defined like this.
m! = m(m - 1)(m - 2)(m - 3)...(m - m + 1)
if you start from zero, rather than m, you get the exact same answer but it's much easier to calculate.
1 * 2 * 3 * 4 ... * m
Extending this for non integral factorials seems like it would be as simple as
1a * 2a * 3a * 4a ... *ma
Which can be simplified to
a^m * m!
Here, "a" could be any type of number, positive, negative, real, even complex and it seems to be a simple, logical way to extend factorials, so I'm wondering why the gamma is so complex, incorporating integrals, "e" limits etc... and what benefits that complexity adds to the mix.
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