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Math:Probability:Distribution:Gamma:Can you describe Gamma distribution C^k.e^(-C.T).T^(k-1)/(k-1)!?

Dec 28th, 2004 09:23
Knud van Eeden,


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--- Knud van Eeden --- 28 December 2004 - 05:50 pm -------------------

Math:Probability:Distribution:Gamma:Can you describe Gamma 
distribution C^k.e^(-C.T).T^(k-1)/(k-1)!?

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Definition of the Gamma probability function.

   k    -(C.T)    (k-1)
= C  . e       . T                                                 (1)
  ---------------------
       Gamma( k )

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The gamma distribution is a special case of a continuous probability
distribution.

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The gamma distribution is a general type of statistical distribution
(occurring e.g. in processes in which you want to know the
waiting time intervals between events described by Poisson
distributions, like the waiting time between telephone calls)

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You can derive it by differentiating its cumulative probability
function, which is a sum of Poisson distributions.

See e.g. the Erlang distribution description for a derivation,
otherwise [Eric Weisstein]

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History:

Appeared first in statistics in the 1930s
(used by Karl Pearson and later Charles Ernest Weatherburn)

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Note:

'Gamma family' of distributions:

The exponential distribution, Poisson distribution and Gamma
distribution are sometimes called the 'Gamma family',
so clearly indicating, emphasizing and associating that it is a group,
collection belonging together.

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Book: see also:

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[book: Drake, Alvin W. - Fundamentals of Applied Probability Theory - 
Mcgraw-Hill - http://www.amazon.com/exec/obidos/tg/detail/-
/0070178151/qid=1104254766/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/104-5080812-
8575144?v=glance&s=books&n=507846]

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[book: Hastings, Kevin J. - Probability and statistics - ISBN 0-201-
59278-9 - p. 133-140 'Gamma density' (good description, also 
explaining briefly the link between a Poisson process interval and the 
exponential function). Calls the exponential distribution, Poisson 
distribution and Gamma distribution the 'Gamma family')]

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[book: Ross, Sheldon M. - Introduction to Probability Models - 
http://www.amazon.com/exec/obidos/ASIN/0125980558/qid=1104254849/sr=2-
1/ref=pd_ka_b_2_1/104-5080812-8575144]

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[book: Spanier, Jerome / Oldham, Keith B. - an atlas of functions - 
ISBN 0-89116-573-8 - p. 260 'Gamma distribution' (only some formulas 
with a short description)]

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[book: Weisstein, Eric - CRC encyclopedia mathematics - p. 694 'Gamma 
distribution' (a good description, lots of formulas and a few graphs)]

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[book: Zwillinger, Daniel - CRC standard mathematical tables and 
formula - p. 584 'Gamma distribution' (only some formulas with a short 
description)]

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Internet: see also:

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Gamma distribution: history
http://members.aol.com/jeff570/g.html

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Charles Ernest Weatherburn
http://www-groups.dcs.st-
and.ac.uk/~history/Mathematicians/Weatherburn.html

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Karl Pearson
http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Pearson.html

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Gamma distribution (showing graphs)
http://en.wikipedia.org/wiki/Gamma_distribution

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Gamma distribution (Showing a graph / see (5) 'The corresponding 
probability function P(x) of waiting times until the hth Poisson event 
is then obtained by differentiating D(x)')
http://mathworld.wolfram.com/GammaDistribution.html

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Math: Probability: Distribution: Link: Overview: Can you give an 
overview of links?
http://www.faqts.com/knowledge_base/view.phtml/aid/32917/fid/815

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