Package statistics: tricdf (bug?)

[Evangelos Rozos]

I think something is wrong with tricdf function (maybe triinv also).

>> tricdf (0.7, 0.5, 1.0, 0.9)

ans =  0.16000

The correct answer should be 0.2.

MATLAB gives 0.2. This value can be also verified by the geometry of the 
pdf triangle with base from 0.5 to 1, and height 4 at 0.9. Then, the 
area of the triangle with base from 0.5 to 0.7 and height 2 (0.7 is in 
the middle of the 0.5 to 0.9 segment) is 0.2.