[Maxima-bugs] [ maxima-Bugs-2821277 ] inverse_jacobi_sn(x,0)

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Bugs item #2821277, was opened at 2009-07-14 13:21
Message generated for change (Comment added) made by crategus
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Category: Lisp Core - Simplification
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Barton Willis (willisbl)
Assigned to: Nobody/Anonymous (nobody)
Summary: inverse_jacobi_sn(x,0)

Initial Comment:
inverse_jacobi_sn(x,0)  simplifies to (($ASIN SIMP) $X) , but I think it should be  ((%ASIN SIMP) $X) . One problem this causes is:

(%i109) inverse_jacobi_sn(x,0);
(%o109) asin(x)

(%i110) diff(%,x);
(%o110) 'diff(asin(x),x,1)

(%i111) ev(%,diff);
(%o111) 1/sqrt(1-x^2)




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>Comment By: Dieter Kaiser (crategus)
Date: 2009-07-14 20:26

Message:
Further comment:

The functions elliptic_e and elliptic_f are implemented as simplifying
functions with the symbol $elliptic_e and $elliptic_f. The noun-form of
this symbols is not known to Maxima and there is no alias and reversealias
on the property list.

In this case the simplified expression has to contain the $-name too. By
the way: We can produce some inconsistencies when implementing a function
this way.

Dieter Kaiser

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Comment By: Dieter Kaiser (crategus)
Date: 2009-07-14 20:18

Message:
Yes, I think $asin has to be changed to %asin.

Remark: For all simlifying functions with an alias and reversealias on the
property list only the noun form "%function " can be used in simplified
Maxima expressions. This is the case for most elementary functions like the
trig funtions. There are some exceptions like the beta function. I think
this is inconsistent.

Dieter Kaiser

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Comment By: Raymond Toy (rtoy)
Date: 2009-07-14 19:43

Message:
Probably caused by confusion of noun/verb.  The offending code is line
1094:

	  ((zerop1 m)
	   ;; asn(x,0) = F(asin(x),0) = asin(x)
	   (take '($asin) u))

Should that be %asin?   There are other places where this happens.


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