wp34s binomial bug

[Andrew Nikitin]

0.5 STO J

2 STO K

2 h PROB Binom

Gives "Domain error" instead of 1.
Binom_u also gives incorrect result.

[Dieter]

First of all: which firmware version do you refer to?

I get the following results with v3.2 3405.

Just to be sure:

• "Binom"  evaluates the lower CDF, i.e. the sum of all probabilities from k = 0...X
  
• "Binom_u" evaluates the upper CDF, i.e. the sum of all probabilities from k = X...n
  
• "Binom_p" evaluates the PDF, i.e. the single probability for k = X.

All this works fine here:

 0,5 STO J

  2  STO K

 

  0  Binomp   => pdf(0) = 0,25

  1  Binomp   => pdf(1) = 0,5

  2  Binomp   => pdf(2) = 0,25

 

  0  Binom    => lower cdf(0) = 0,25   (= pdf(0))

  1  Binom    => lower cdf(1) = 0,75   (= pdf(0) + pdf(1)) 

  2  Binom    => lower cdf(2) = 1      (= pdf(0) + pdf(1) + pdf(2))

 

  0  Binomu   => upper cdf(0) = 1      (= pdf(0) + pdf(1) + pdf(2))

  1  Binomu   => upper cdf(1) = 0,75   (= pdf(1) + pdf(2))

  2  Binomu   => upper cdf(2) = 0,25   (= pdf(2))

What do you get?

Dieter

Edited: 22 Sept 2013, 2:34 p.m.

[Miguel Toro]

Hi,

I also checked with mine: Version 3.2 3450

Results:

  0  Binom    => 0,25

  1  Binom    => 0,75 

  2  Binom    => Domain Error

Cheers,

Miguel

[Andrew Nikitin]

I discovered it on actual unit, which I do not have with me, but tried it with latest build in emulator (3450) before posting.

I get Domain error on Binom(2) everything else works like your example.

[Paul Dale]

Bug fixed.

- Pauli