Post Reply 
(35S) Statistical Distributions Functions
10-25-2015, 01:29 PM
Post: #2
RE: HP 35s Statistical Distributions Functions
The HP 35s has two features that are missing in the HP-67:
  • integration
  • gamma function by using \(\Gamma(n)=(n-1)!\)

Thus I wouldn't recommend to translate these HP-67 programs directly to the HP 35s. I just had a quick look at Chi-Square Distribution for the HP-67 and it uses a series approximation to evaluate the cumulative distribution. With the HP 35s you can use numeric integration instead.

Just have a look at the program Normal and Inverse–Normal Distributions in the user's guide (pp 16-11). You can replace the subroutine F that calculates the integrand for the normal distribution. It calculates the "upper tail" area but that is easy to change. Since integration and solver can't be mixed a Newton-iteration is used to calculate the inverse. The calculation of the derivative is just evaluating the probability density function due to the fundamental theorem of calculus.

Let us know if you struggle to translate the formulas of the probability density functions to programs. Using an algebraic equation might be easier but will be probably slower.

Find all posts by this user
Quote this message in a reply
Post Reply 

Messages In This Thread
RE: HP 35s Statistical Distributions Functions - Thomas Klemm - 10-25-2015 01:29 PM

User(s) browsing this thread: 1 Guest(s)