[Maxima-bugs] [ maxima-Bugs-531466 ] float needs to be eval. with numer

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Bugs item #531466, was opened at 2002-03-18 11:09
Message generated for change (Comment added) made by robert_dodier
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Category: Lisp Core
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Daniel Lemire (lemire)
Assigned to: Nobody/Anonymous (nobody)
Summary: float needs to be eval. with numer

Initial Comment:
See below... we'd like to see "float(exp(exp(2)))" evaluated 
to 1618.177991912654.

(C1) float(exp(exp(2)));

                                                2
                                              %E
(D1)                         2.718281828459045
(C2) float(exp(exp(2))),numer;

(D2)                           1618.177991912654
(C3)


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>Comment By: Robert Dodier (robert_dodier)
Date: 2006-03-26 16:50

Message:
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More of the same: [ 609464 ] 1+%e,numer and %e^%e,numer

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Comment By: Robert Dodier (robert_dodier)
Date: 2006-03-26 16:46

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See also [ 586688 ] numer and float problem. (more of the
same, with different examples).

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Comment By: Robert Dodier (robert_dodier)
Date: 2006-03-26 16:18

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For the record, same behavior for all examples in Maxima 5.9.3.

(%i10) float(exp(exp(2)));
(%o10) 2.718281828459045^%e^2
(%i11) float(exp(exp(2))), numer;
(%o11) 1618.177991912654
(%i12) float(%pi^%pi);
(%o12) 3.141592653589793^%pi
(%i13) float(2^%pi);
(%o13) 2.0^%pi
(%i14) float((%e+%pi)^2);
(%o14) 34.33812894536713


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Comment By: Stavros Macrakis (macrakis)
Date: 2004-02-23 16:51

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More cases: float(%pi^%pi)=> 3.14^%pi; float(2^%pi)
=>2.0^%pi; but float((%e+%pi)^2) => 34.3.
 
The intent is to avoid floating powers of symbolic objects.  
For example, you don't want float(x^2)=>x^2.0 or float(x^
(1/3)) => x^0.333.  But obviously this has been taken too 
far.  If we can get a numerical result for the whole 
expression, we should (2^%e, %e^2, even %e^%pi).

Numer and float just aren't very well thought-out.


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