Robert Dodier wrote:
> On Mon, Mar 24, 2008 at 9:45 AM, Raymond Toy (RT/EUS)
> <raymond.toy at ericsson.com> wrote:
>
>> While playing with donlp2, I noticed that maxima orders vector variables
>> in "reverse" order. For example,
>>
>> sum(x[k],k,1,5) -> x[5]+x[4]+x[3]+x[2]+x[1].
>>
>> While I usually just accept whatever order maxima wants to display
>> variables, this particular example seems wrong. There's a natural
>> ordering and it's by the index of the variable.
>>
>> Any reason why it should be in reverse order? Any objections to
>> changing it for this case? (I don't know if that's really possible or
>> not. I haven't looked.)
>
> The terms x[1], x[2], ... are stored in order of increasing index.
> Whether they are displayed that way or reversed is controlled
> by the global variable powerdisp. When powerdisp=true the terms
> are displayed in order of increasing index.
So many globals! powerdisp certainly does what I want, but it also
changes how polynomials are displayed. I always want vectors displayed
in increasing order of index, but polynomials are different.
But this works for me. No need to change the default.
>
> I'm not opposed to changing the default value of powerdisp to true.
>
> Aside from changing powerdisp, we could also change GREAT
> (the function which implements Maxima's idea of canonical
> ordering). Changing GREAT could have rippling effects, though.
If I were to make such a change, I would have it only affect arrays, and
maybe only 1D arrays. That should limit the effects.
But powerdisp suits me for now.
Thanks,
Ray