Re: [Maxima-discuss] a(b), a[b], op, args

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Hi Stavros,

I just tested your function show_expression from

  https://sourceforge.net/p/maxima/mailman/message/58795759/

on factorized numbers and on three flavors of power series: plain,
"trunc", and "taylor"... it turned out that "inflag:true", is enough
to make factorized numbers be displayed correctly - as products of
powers - but your show_expression doesn't have support for telling if
a power series would be displayed with a "...", with a "/T/", or both.

Would that be easy to fix?

Here is the code:

--snip--snip--
show_expression(ex):=
   if atom(ex) then ex
   elseif subvarp(ex) then
funmake('subsc,cons(op(ex),[maplist(show_expression,args(ex))]))
   elseif ratnump(ex) then funmake('rat,[first(ex),second(ex)])
   elseif mapatom(ex) then ex
   elseif member(part(ex,0), show_special)
     then funmake(show_expression_name[part(ex,0)],
maplist(show_expression,args(ex)))
   elseif not(atom(part(ex,0)))
     then
funmake('apply,[show_expression(part(ex,0)),maplist(show_expression,args(ex))])
   else block([pex:part(ex,0)],
       funmake(concat(if nounify(pex)=pex then 'N else 'V,pex),
maplist(show_expression,args(ex))))$

show_special: []$
for i in
  '[["+",add],     ["-",minus], ["*",mul], ["^",power], ["/",div],
    [".",ncmul],   ["^^", ncpower],
    ["[",list],    ["{",set],
    [":",assign],  ["::",varassign],
    [":=",define], ["::=",definemac]
    ["'",quote],     ["(",prog],
    ["=",equal],     ["#",notequal], [">",greaterp],[">=", greatereq],
["<", lessp], ["<=",lesseq],
    ["!",factorial], ["@",field]
    ]
  do (show_expression_name[first(i)]: second(i),
push(first(i),show_special));

a : factor(1000);                 "shows a as 2^3 * 5^3"$
show_expression(a), inflag:true;  "shows a as 2^3 * 5^3"$
show_expression(a);               "shows a as   8 * 125"$

linel : 100;
b1 : 1 + 2*x + 2*x^2 + 4/3*x^3;
b2 : trunc(b1);                   "has a ..."$
b3 : taylor(exp(2*x), x, 0, 3);   "has a ... and a /T/"$
show_expression(b1);
show_expression(b1), inflag:true;
show_expression(b2);
show_expression(b2), inflag:true;
show_expression(b3);
show_expression(b3), inflag:true;
--snip--snip--

...and the relevant part of the output:

--snip--snip--
(%i22) b1 : 1 + 2*x + 2*x^2 + 4/3*x^3;
                                          3
                                       4 x       2
(%o22)                                 ──── + 2 x  + 2 x + 1
                                        3
(%i23) b2 : trunc(b1);                   "has a ..."$
                                                       3
                                                2   4 x
(%o23)                             1 + 2 x + 2 x  + ──── + . . .
                                                     3
(%i25) b3 : taylor(exp(2*x), x, 0, 3);   "has a ... and a /T/"$
                                                       3
                                                2   4 x
(%o25)/T/                          1 + 2 x + 2 x  + ──── + . . .
                                                     3
(%i27) show_expression(b1);
(%o27)          add(div(mul(4, power(x, 3)), 3), mul(2, power(x, 2)),
mul(2, x), 1)
(%i28) show_expression(b1), inflag:true;
(%o28)          add(1, mul(2, x), mul(2, power(x, 2)), mul(rat(4, 3),
power(x, 3)))
(%i29) show_expression(b2);
(%o29)          add(1, mul(2, x), mul(2, power(x, 2)), div(mul(4, power(x,
3)), 3))
(%i30) show_expression(b2), inflag:true;
(%o30)          add(1, mul(2, x), mul(2, power(x, 2)), mul(rat(4, 3),
power(x, 3)))
(%i31) show_expression(b3);
(%o31)          add(1, mul(2, x), mul(2, power(x, 2)), div(mul(4, power(x,
3)), 3))
(%i32) show_expression(b3), inflag:true;
(%o32)      mul(rat(1, 3), add(3, mul(6, x), mul(6, power(x, 2)), mul(4,
power(x, 3))))
(%i33)
--snip--snip--

  Cheers =),
    Eduardo Ochs
    http://anggtwu.net/eev-maxima.html

On Mon, 15 Jul 2024 at 19:43, Stavros Macrakis <mac...@gm...> wrote:

> Here's a little quick-and-dirty code to show the internal form of a Maxima
> expression as a functional expression.
> Of course, you could just look at the Lisp....
>
> Examples:
>
> show_expression( -2/3*(a-b)/(b*sqrt(5)) )                       <<< with
> inflag:false (default), show the user-friendly version
>    =>  sub(div(mul(2, add(a, sub(b))), mul(3, xsqrt(5), b)))
>
> It uses function names for operators.
>
> show_expression( -2/3*(a-b)/(b*sqrt(5)) ),inflag:true;
>  <<< with inflag:true, show the actual internal version
>    => mul(rat(- 2, 3), power(5, rat(- 1, 2)), add(a, mul(- 1, b)),
> power(b, - 1))
>
> grind(%), linel=30.      << pretty-print -- choose linel to control
> appearance
> =>
>
> mul(rat(-2,3),
>     power(5,rat(-1,2)),
>     add(a,mul(-1,b)),
>     power(b,-1))$
>
>
> It shows verb-functions as V*name* and noun-functions as N*name*.
>
> show_expression('[integrate(x,x), 'integrate(x,x)]);
>      =>   list(Vintegrate(x, x), Nintegrate(x, x))
>
> It doesn't do anything special for *if, do*, etc. since the internal form
> is just a list of arguments:
>
> show_expression('(if a then b else c))
>    => Vif(a, b, true, c)
>
> show_expression('(for i thru 4 do print(i)))
>    => Vdo(i, false, false, false, 4, false, Vprint(i))
>
> show_expression('(for i:2 thru 4 while i^2 < 10 do print(i)))
>    =>  Vdo(i, 2, false, false, 4, greatereq(power(i, 2), 10), Vprint(i))
>
> show_expression('(for i:2 step 1/2 thru 4  while i^2 < 10 do print(i)))
>    =>  Vdo(i, 2, rat(1, 2), false, 4, greatereq(power(i, 2), 10),
> Vprint(i))
>
> show_expression('(for i:2 thru 4 next i+1/3 while i^2 < 10 do print(i)))
>    =>  Vdo(i, 2, false, add(i, rat(1, 3)), 4, greatereq(power(i, 2), 10),
> Vprint(i))
>
> show_expression('(for i in [a,b,c] do print(i)))
>    =>  Vdo_in(i, list(a, b, c), false, false, false, false, Vprint(i))
>
>
> ----------------
>
> /* Show Maxima expression in explicit form.
>
> For example, with inflag:false (the default):
>
>     show_expression((a[3]-3)/sqrt(5)) => f/(plus(subsc(a,3),-3),sqrt(5))
>
> with inflag:true (to show the internal form):
>
>     show_expression(a[3]/sqrt(5)) => f*(f^(5,rat(-1,2)),subsc(a,3))
>
> */
>
> show_expression(ex):=
>    if atom(ex) then ex
>    elseif subvarp(ex) then
> funmake('subsc,cons(op(ex),[maplist(show_expression,args(ex))]))
>    elseif ratnump(ex) then funmake('rat,[first(ex),second(ex)])
>    elseif mapatom(ex) then ex
>    elseif member(part(ex,0), show_special)
>      then funmake(show_expression_name[part(ex,0)],
> maplist(show_expression,args(ex)))
>    elseif not(atom(part(ex,0)))
>      then
> funmake('apply,[show_expression(part(ex,0)),maplist(show_expression,args(ex))])
>    else block([pex:part(ex,0)],
>        funmake(concat(if nounify(pex)=pex then 'N else 'V,pex),
> maplist(show_expression,args(ex))))$
>
> show_special: []$
> for i in
>   '[["+",add], ["-",minus], ["*",mul], ["^",power], ["/",div],
>     [".",ncmul], ["^^", ncpower],
>     ["[",list], ["{",set],
>     [":",assign], ["::",varassign],
>     [":=",define], ["::=",definemac]
>     ["'",quote], ["(",prog],
>     ["=",equal], ["#",notequal], [">",greaterp],[">=", greatereq], ["<",
> lessp], ["<=",lesseq],
>     ["!",factorial], ["@",field]
>     ]
>   do (show_expression_name[first(i)]: second(i),
> push(first(i),show_special));
>
>
>
> On Fri, Jul 12, 2024 at 2:10 PM Eduardo Ochs <edu...@gm...>
> wrote:
>
>> Hi Robert -
>> Fixed! See:
>>   https://github.com/edrx/luatree/blob/main/luatree2.mac
>>
>> Example:
>>
>>   (%i1) load("~/luatree/luatree2.mac")$
>>   (%i2) luatree  (a(b,c))$
>>   a__.
>>   |  |
>>   b  c
>>   (%i3) luatree  (a[1][2](b,c))$
>>   ap_________.__.
>>   |          |  |
>>   [_]_____.  b  c
>>   |       |
>>   [_]__.  2
>>   |    |
>>   a    1
>>   (%i4) luatree  (a[1][2](b,c)(d))$
>>   ap_______________.
>>   |                |
>>   ap_________.__.  d
>>   |          |  |
>>   [_]_____.  b  c
>>   |       |
>>   [_]__.  2
>>   |    |
>>   a    1
>>   (%i5)
>>
>> [[]], E.
>>
>>
>>
>> On Fri, 12 Jul 2024 at 13:40, Robert Dodier <rob...@gm...>
>> wrote:
>>
>>> On Fri, Jul 12, 2024 at 12:13 AM Eduardo Ochs <edu...@gm...>
>>> wrote:
>>>
>>> > "op" and "args" don't distinguish between a(b) and a[b]:
>>> >
>>> >   (%i1) [o:a(b),op(o),args(o)];
>>> >   (%o1)                           [a(b), a, [b]]
>>> >   (%i2) [o:a[b],op(o),args(o)];
>>> >   (%o2)                            [a , a, [b]]
>>> >                                      b
>>> >   (%i3)
>>> >
>>> > what do I need to use to distinguish them?
>>>
>>> In the luatree code, try changing atom(something) to
>>> mapatom(something) -- atom(a[b]) returns false but mapatom(a[b])
>>> returns true.
>>>
>>> In addition to stuff like a[b], you may wish to cover stuff like
>>> a[b](x, y), a(b)(x, y), a[b](x, y)(z), which are all legitimate Maxima
>>> expressions ... I guess you just need to be prepared for op(something)
>>> returning a non-mapatom.
>>>
>>> All the best,
>>>
>>> Robert
>>>
>> _______________________________________________
>> Maxima-discuss mailing list
>> Max...@li...
>> https://lists.sourceforge.net/lists/listinfo/maxima-discuss
>>
>

Re: [Maxima-discuss] a(b), a[b], op, args

Computer Algebra System written in Common Lisp

Re: [Maxima-discuss] a(b), a[b], op, args