Typographical issues with the Maxima-plugin returning integral expressions in mathematical output

Tilda · May 12, 2022, 3:33pm

For my liking, the spacing before the d and the variable x that the Maxima-plugin generates is much too large:

I’d rather have this spacing of <space | 0.27em>

be replaced by <space | 0.24em> before the d and <space | 0.08em> before the variable x automatically by the plugin as

produces typographically more pleasing results:

So my question, where exactly (i.e in which of the plugin files) can this be fixed.

Cheers
Tilda

jeroen · May 12, 2022, 5:36pm

My guess is here:

github.com

texmacs/plugins/blob/master/maxima/lisp/texmacs-maxima.lisp#L111


    "}"
    ,@r)))


;; Integrals, sums, products


(texmacs-no-warning
(defun tex-int (x l r)
  (let ((s1 (tex (cadr x) nil nil 'mparen 'mparen)) ;;integrand delims / & d
	(var (tex (caddr x) nil nil 'mparen rop))) ;; variable
    (cond((= (length x) 3)
	  (append l `("\\int {" ,@s1 "}{\\;\\mathd\\;" ,@var "}\\big.") r))
	 (t ;; presumably length 5
	  (let ((low (tex (nth 3 x) nil nil 'mparen 'mparen))
		;; 1st item is 0
		(hi (tex (nth 4 x) nil nil 'mparen 'mparen)))
	    (append l `("\\int_{" ,@low "}^{" ,@hi "}{" ,@s1 "\\;\\mathd\\;" ,@var "}\\big.") r)))))))


(texmacs-no-warning
(defun tex-sum(x l r)
  (let ((op (cond ((eq (caar x) '%sum) "\\sum_{")
		  ((eq (caar x) '%product) "\\prod_{")

Tilda · May 12, 2022, 6:08pm

Thanks for your fast reply @jeroen! Does the LaTeX instruction \; translate into 0.27em? If I remember correctly, there are corresponding instructions \: and \, but I’ve forgotten which of then produce bigger or smaller horizontal spacing in math mode.

Is there a way to numerically define that?

Cheers
Tilda

jeroen · May 12, 2022, 6:16pm

You can check what spacing you will get by copying e.g. \; and then doing Paste from LaTeX.

Tilda · May 12, 2022, 7:14pm

After checking as you suggested, @jeroen, I figured out that LaTeX \; does indeed translate into <space|0.27em>, \: into <space|0.22em> and \, into <space|0.17em>. The latter being obviously the delimiter the Reduce plugin uses.

Tilda

jeroen · May 12, 2022, 7:26pm

The spacing does look off to me as well. Perhaps you could file a bug report?

Tilda · May 13, 2022, 6:01pm

Dear @jeroen before I file a bug report to Savannah, I would like to ask your opinion.

I modified lines 111 and 116 of texmacs-maxima.lisp the following way:

(append l `("\\int {" ,@s1 "}{\\,\\mathd\\hspace{0.05em}" ,@var "}\\big.") r))

	    (append l `("\\int_{" ,@low "}^{" ,@hi "}{" ,@s1 "\\,\\mathd\\hspace{0.05em}" ,@var "}\\big.") r)

The plugin thus automatically creates <space | 0.17em> before the d and <space | 0.05em> before the variable x.

which produces typographically much better output than before:

What do you think?

Cheers
Tilda

jeroen · May 13, 2022, 6:34pm

That looks a lot better than the original
It seems there is a multiplication appearing after the d and after sin(x), which probably adds some more space. The one before d is okay, but the one after is not necessary. It would be good to find out where it comes from. I just normally don’t use any additional spacing in integrals, I just have one multiplication before the d.

Tilda · May 13, 2022, 7:02pm

It does not come from the space before ,@var in ll. 111 and 116. of the above mentioned lisp file. I have no idea why Texmacs inserts a * in-between dx and after the function term. The reduce plugin btw. exhibits the same behaviour.

Tilda · May 13, 2022, 7:14pm

copy and pasting the rhs of the equation in the mathematically formatted output in (o%3) into a maxima input line yields

which is not quite the same as the original input integrate(x*sin(x),x).

Looks as if this is more than just a formatting issue.

Tilda · May 13, 2022, 7:22pm

should read: copy and pasting the lhs

Tilda · May 18, 2022, 5:06pm

I filed the bug report. For your reference: https://savannah.gnu.org/bugs/index.php?62488