Re: [Maxima-discuss] Include Nabla Greek Symbol

[Robert D. <rob...@gm...>]

On Thu, Dec 19, 2019 at 5:16 PM Fraser Doswell <dos...@ac...> wrote:
>
> A real Nabla symbol would be very useful for published mathematics and
> physics papers.
>
> Is there a way to create or use an existing font symbol and include it
> in the wxmaxima symbol panes on the left?

Hi Fraser, I don't know about wxMaxima but in command line Maxima it
is straightforward to display an operator with a special symbol.
Maxima is Unicode-compatible if compiled with a Unicode-compatible
Lisp, which is all of the existing Lisp implementations except for
GCL. So one can use a Unicode nabla symbol, either as the display
symbol for a function named "grad", let's say, or as the name of the
function itself.

(%i2) prefix ("grad") $
(%i3) :lisp (setf (get '$grad 'dissym) (list #\nabla))
(∇)
(%i3) grad F(x,y);
(%o3)                       ∇F(x, y)
(%i4) prefix ("∇");
(%o4)                           ∇
(%i5) ∇ G(u,v);
(%o5)                       ∇ G(u, v)

Another option, which is especially relevant if one is composing
formulas to put in publications, is to assign the TeX property for
"grad".

(%i6) texput ("grad", "\\nabla ", prefix);
(%o6)                        \nabla
(%i7) tex (grad H(a,b,c));
$$\nabla H\left(a , b , c\right)$$
(%o7)                         false

(%i10) texput ("∇", "\\nabla ", prefix);
(%o10)                       \nabla
(%i11) tex (∇ Z(u,v,w));
$$\nabla Z\left(u , v , w\right)$$
(%o11)                        false

Hope this helps in some way -- maybe if you say more about what you're
working on, someone will be able to give more specific advice. I think
there is a similar way to set display properties in wxMaxima but I
don't know the details.

best,

Robert Dodier