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#1427 a misprint about radcan() in the manual

closed
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5
2008-06-07
2008-06-02
No

Dear Developers of Maxima,

I found a misprint in the description of radcan()
in Maxima manual (both of pdf and online versions).

This part of the description of radcan() in Maxima 5.14.0cvs is as follows:
-------------------------------------------------------------------------------
[Macintosh:/tmp:1] adachi% maxima --batch-string='? radcan'
Maxima 5.14.0cvs http://maxima.sourceforge.net
Using Lisp GNU Common Lisp (GCL) GCL 2.6.7 (aka GCL)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) describe(radcan, exact)

-- Function: radcan (<expr>)
...
...

When `radexpand' is `false', certain transformations are inhibited.
`radcan (sqrt (1-x))' remains `sqrt (1-x)' and is not simplified
to `%i sqrt (x-1)'. `radcan (sqrt (x^2 - 2*x + 11))' remains
`sqrt (x^2 - 2*x + 1)' and is not simplified to `x - 1'.

...
...
-------------------------------------------------------------------------------

The misprint is as follows:

WRONG:

`radcan (sqrt (x^2 - 2*x + 11))' remains `sqrt (x^2 - 2*x + 1)' ...

CORRECT:

`radcan (sqrt (x^2 - 2*x + 1))' remains `sqrt (x^2 - 2*x + 1)' ...

I inspected the corresponding description in an old manual
"Macsyma Mathematics and System Refercen Manual" (16th Edition)
published by Macsyma, Inc. in 1996.

On p.37 in this Macsyma manual, it is written as

radexpand default: true
When set to false, this option variable inhibits certain transformations:
... ; and radcan(sqrt(x^2-2+1)) remains sqrt(x^2+2x+1) and is not transformed
to x-1. ...

Clearly, the above description in Maxima manual comes from this part in
the old Macsyma manual. So, I think that the misprint is confirmed.

Please correct the misprint.

Sincerely yours,
Satoshi Adachi

P.S. Furthermore, radcan() does not work as is described
in the corrected manual. This is a bug of radcan().
I will report this bug in a separate report.

Discussion

  • Dan Gildea

    Dan Gildea - 2008-06-07

    Logged In: YES
    user_id=1797506
    Originator: NO

    fixed in Simplification.texi rev 1.20

     
  • Dan Gildea

    Dan Gildea - 2008-06-07
    • status: open --> closed
    • assigned_to: nobody --> dgildea
     

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