(42S) Weibull UTPW

[Gerald H]

Weibull distribution is referenced with various parameters, the form I prefer is

(B/A)*((X-G)^(B-1))*e^(((X-G)^B)/A)

A, B & G customarily read as alpha, beta & gamma.

Happily the integral with respect to X has a closed form

e^-((e^(B*LN(X-G)))/A)



0. { 35-Byte Prgm }
1. †LBL "W¨P"
2. X<>Y
3. -
4. LN
5. ×
6. E^X
7. X<>Y
8. ÷
9. +/-
10. E^X
11. RTN
12. †LBL "P¨W"
13. LN
14. +/-
15. RCL× ST T
16. LN
17. RCL÷ ST Z
18. E^X
19. +
20. END


Eg 7, 8, 11, .01 P¨W returns 12.5436

Eg 7, 8, 11, 12.5 W¨P returns 0.0257