Maxima -- GPL CAS based on DOE-MACSYMA / Bugs / #2285 float hypergeometric error

#2285 float hypergeometric error | fix

Status: closed

Owner: Barton Willis

Labels: None

Priority: 5

Updated: 2011-11-28

Created: 2011-10-21

Creator: Barton Willis

Private: No

Bogus:

(%i1) hypergeometric([1],[3/2,3/2], -10000.0),fpprec : 56;
(%o1) 4.3929157271741888*10^65

OK:

(%i2) hypergeometric([1],[3/2,3/2], -10000.0b0),fpprec : 56;
(%o2) -4.0120302702491972103831671317134763299116280927551908191b-4

Putative fix: In hypergeometric-by-series, replace

;; estimate number of correct digits:
\(setq dig \(floor 
       \(\*
        \(- \(log \(max \(abs s\) \(epsilon \(bigfloat x\)\)\)\) \(log \(\* es \(epsilon \(bigfloat x\)\)\)\)\)
        \#.\(/ \(log 2\) \(log 10\)\)\)\)\)

with

    \(setq dig \(floor 
       \(\*
        \(- \(log \(max \(abs s\) \(epsilon x\)\)\) \(log \(\* es \(epsilon x\)\)\)\)
        \#.\(/ \(log 2\) \(log 10\)\)\)\)\)

Discussion

Barton Willis - 2011-11-28

fixed by Commit:6209d4d40f52f7c7a82e57ef2dfe82470fc85ebe

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Barton Willis - 2011-11-28

status: open --> closed
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float hypergeometric error | fix

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#2285 float hypergeometric error | fix

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