[Maxima-bugs] [ maxima-Bugs-3067130 ] binomial(1/2,1/3),nouns

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Bugs item #3067130, was opened at 2010-09-15 23:12
Message generated for change (Comment added) made by crategus
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Category: Lisp Core - Simplification
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 5
Private: No
Submitted By: Dieter Kaiser (crategus)
Assigned to: Nobody/Anonymous (nobody)
Summary: binomial(1/2,1/3),nouns

Initial Comment:
The function binomial has an unusual definition for the verb function:

(defmfun $binomial (x y)
  (let (($numer t) ($float t))
    (simplify (list '(%binomial) x y))))

In addition to other simplifying functions the flags $numer and $float are set to T. This causes a different behavior.

The verb function is called when the evflag NOUNS is used. This is the behavior of a standard simplifying function. The evflag NOUNS does not force evaluation:

(%i2) sin(1/2);
(%o2) sin(1/2)

(%i3) sin(1/2),nouns;
(%o3) sin(1/2)

(%i4) sin(1/2),float;
(%o4) 0.479425538604203

The binomial functions evaluates numerically with the evflag NOUNS:

(%i5) binomial(1/2,1/3);
(%o5) binomial(1/2,1/3)

(%i6) binomial(1/2,1/3),nouns;
(%o6) 1.06976119171899

I think there is no reason to have a different definition for the binomial function.

Dieter Kaiser

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>Comment By: Dieter Kaiser (crategus)
Date: 2010-09-24 21:46

Message:
Fixed in csimp2.lisp revision 1.44.
Closing this bug report as fixed.
Dieter Kaiser


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