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#334 Misrecognized variable in Expression. ←	↑	→ #336 'binomial$COMBF' is not evaluated consistently

#335 sort! drops list elements

Edit detail for #335 sort! drops list elements revision 3 of 3

	1 2 3
Editor: test1 Time: 2018/05/10 20:21:49 GMT+0
Note:

added:

From test1 Thu May 10 20:21:49 +0000 2018
From: test1
Date: Thu, 10 May 2018 20:21:49 +0000
Subject: 
Message-ID: <20180510202149+0000@axiom-wiki.newsynthesis.org>

Status: open => closed

the following commands:

fricas

(1) -> bb:=[1,1,2,2,2,2,1,1,1,3,1]

$\label{eq1}\left[ 1, \: 1, \: 2, \: 2, \: 2, \: 2, \: 1, \: 1, \: 1, \: 3, \: 1 \right]$

(1)

Type: List(PositiveInteger?)

fricas

sort! bb

$\label{eq2}\left[ 1, \: 1, \: 1, \: 1, \: 1, \: 1, \: 2, \: 2, \: 2, \: 2, \: 3 \right]$

(2)

Type: List(PositiveInteger?)

fricas

bb

$\label{eq3}\left[ 1, \: 1, \: 2, \: 2, \: 2, \: 2, \: 3 \right]$

(3)

Type: List(PositiveInteger?)

return:

  bb = [1,1,2,2,2,2,3]

is sort! only intended for lists without repetition?

fricas

bb:=[1,1,2,2,2,2,1,1,1,3,1]

$\label{eq4}\left[ 1, \: 1, \: 2, \: 2, \: 2, \: 2, \: 1, \: 1, \: 1, \: 3, \: 1 \right]$

(4)

Type: List(PositiveInteger?)

fricas

bb := sort! bb

$\label{eq5}\left[ 1, \: 1, \: 1, \: 1, \: 1, \: 1, \: 2, \: 2, \: 2, \: 2, \: 3 \right]$

(5)

Type: List(PositiveInteger?)

fricas

bb

$\label{eq6}\left[ 1, \: 1, \: 1, \: 1, \: 1, \: 1, \: 2, \: 2, \: 2, \: 2, \: 3 \right]$

(6)

Type: List(PositiveInteger?)

All ! functions destroy their arguement - this is as intended.

destroy or modify? --oklhazi, Fri, 09 Feb 2007 02:11:40 -0600 reply

Thanks for clarification. The manual says that all ! functions modify their arguments and concluded that sort! sorts the list "in place", as stated on p.716 of the Axiom book, i.e., leaving the argument in a sorted state. I realize that "modify" does have different interpretations indeed, including "destroy".

rather a documentation bug --kratt6, Sat, 10 Feb 2007 08:22:23 -0600 reply

Category: Axiom on Linux => Axiom Documentation Severity: serious => normal

why not work as documented? --billpage, Sun, 11 Feb 2007 14:48:24 -0600 reply

It seems to me that the original expectation of the user who submitted this bug and the Axiom Book are both very reasonable. What is the purpose of the modifications that sort! makes to it's argument? To "sort in place" is very reasonable. Why not return this sorted result in the argument as one would expect?

Cleaning issues --Waldek, May 26, 2007 22:11:00 -0500 2007 reply

I have looked at older issues in Issue Tracker and it seems that there are significant number of issues which are just users not understanding what Axiom is doing and expecting different result.

For example 335 sort! drops list elements is just example of linked list. Something like:

 (1) -> bb := [3, 4, 1, 2]

    (1)  [3,4,1,2]
                                                    Type: List PositiveInteger
 (2) -> bs := sort! bb

    (2)  [1,2,3,4]
                                                    Type: List PositiveInteger
 (3) -> bb

    (3)  [3,4]
                                                    Type: List PositiveInteger
 (4) -> bs

    (4)  [1,2,3,4]
                                                    Type: List PositiveInteger
 (5) -> bb.1 := 7

    (5)  7
                                                         Type: PositiveInteger
 (6) -> bs

    (6)  [1,2,7,4]
                                                    Type: List PositiveInteger
 (7) ->

should be, or maybe already is in the tutorial, as an illustration that what was a first element of the list after reorganization may point inside.

... --test1, Wed, 26 Nov 2014 19:53:24 +0000 reply

Severity: normal => minor

... --test1, Thu, 10 May 2018 20:21:49 +0000 reply

Status: open => closed