Talk:Triangular distribution

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The article says: a (location), b (scale) and c (shape) are the triangular distribution parameters. I would have said that c was a more natural location parameter as the mode, b−a the scale (or range and something like \frac{a+b-2c}{2(b-a)} best for the shape, being related to the idea of skewness. --Henrygb 03:31, 25 Mar 2005 (UTC)

[edit] Kurtosis and kurtosis of Triangular distribution?

The kurtosis excess given 12/5 appears to be the 'true' kurtosis?

[@http://mathworld.wolfram.com/TriangularDistribution.html Wolfram ]give the kurtosis excess as -3/5.

which suggests that the value given as excess is in fact the 'true' excess 12/5 (kurtosis excess + 3 = 15/5 -3/5 = 12/5)

Paul A Bristow 18:34, 7 December 2006 (UTC) Paul A Bristow

Right, thanks. Its fixed. PAR 19:31, 7 December 2006 (UTC)

[edit] Formulae for pdf cause divide by zero if a or b = mode

Formulae for pdf cause divide by zero if a or b = c (the mode) (c-a = 0 if c == a). This are the two right angle triagle cases.

In these cases the value is the apex value of 2/(b-a)?

Should this specified separately?

Paul A Bristow 10:27, 11 December 2006 (UTC) Paul A Bristow

With the formulation
f(x|a,b,c)=\left\{ \begin{matrix} \frac{2(x-a)}{(b-a)(c-a)} & \mathrm{for\ } a \le x \le c \\ & \\ \frac{2(b-x)}{(b-a)(b-c)} & \mathrm{for\ } c \le x \le b \end{matrix} \right.
when c=a the first form produces your problem, but the second is fine, even for x=c. I wouldn't bother adding more. --Henrygb 11:26, 11 December 2006 (UTC)
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