Yes... polynomials are a particularly bad use of names. We already
have primitives for dealing with them, and it's rare that there's any
benefit to re-inventing the wheel and doing a less adequate job of it.
Generally speaking, it's good to give names to things that will see a
lot of use.
--
Raul
On Sun, Jan 13, 2013 at 2:56 PM, Kip Murray <k...@math.uh.edu> wrote:
> Thank you, Raul and Henry.
>
> I have used {:: to define "constants" aa bb cc dd and "variables" xx yy zz
> tt but confess that after going to the trouble of defining them I didn't use
> them much. Here they are
>
> aa =: (0 {:: [: : [) :: ([: > [: : [)
> bb =: 1 {:: [: : [
> cc =: 2 {:: [: : [
> dd =: 3 {:: [: : [
>
> xx =: (0 {:: ]) :: ([: > ])
> yy =: 1 {:: ]
> zz =: 2 {:: ]
> tt =: 3 {:: ]
>
> NB. sample use, corresponds to colloquial a x^2 + 2 b x y + c y^2
>
> quadratic =: (aa * xx ^ 2:) + (2 * bb * xx * yy) + cc * yy ^ 2:
>
> 1 1 1 quadratic i. 2 3
> 9 25 49
>
> ((xx + yy)^2:) i. 2 3
> 9 25 49
>
> (xx;yy) i. 2 3
> +-----+-----+
> |0 1 2|3 4 5|
> +-----+-----+
>
> 1 1 1 quadratic 0 1 2 ; 3 4 5
> 9 25 49
>
> Kip Murray
>
>
> On 1/13/2013 11:16 AM, Henry Rich wrote:
>>
>> L: all the time, especially in teaching. The beginners tend to get rank
>> and boxing level confused. The recurring question is "what should you
>> apply this verb on", and if the answer is 'k-cells', you use "k, while
>> if it is 'on the contents of innermost boxes', you use L:0. Last year
>> we had a project (analyzing the text of Hamlet) that ended up with a
>> level-3 boxed array, and L:2, L:1, and L:0 were all meaningful,
>> depending on whether you wanted to work on a word, a line, or a speech.
>>
>> &.> is usually better supported in the interpreter, so I don't use L:0
>> in my own code unless the boxing is heterogeneous.
>>
>> S: I don't use much.
>>
>> L. is also rare.
>>
>> {:: is indispensable when you need it. > 1 { > 2 { y is just harder
>> to read than (2;1) {:: y . It's a pity that 0 {:: scalar fails, or I
>> would use {:: more.
>>
>> Henry Rich
>>
>> On 1/13/2013 1:09 AM, km wrote:
>>>
>>> Have you used members of this family? What for? --Kip Murray
>>>
>>> Sent from my iPad
>>> ----------------------------------------------------------------------
>>> For information about J forums see http://www.jsoftware.com/forums.htm
>>>
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
