Re: eqn formatting issues with grops and gropdf

[joerg van den hoff]

me again with an update/correction to the previous description of the issue (the described problem 
remains, though):

1.
regarding the symobl fonts used by grops and gropdf I previously stated the former were using SS 
(symbols slanted) and the latter S (symbols) which I presumed according to the looks of the greek 
letters in the ps output (upright) and pdf output (slanted to the right like italics). this was *wrong*.
looking into the font information in the formatted files it was the other way around (grops was 
using SS and gropdf using S).

looking into the DESC files, I do find indeed entries

grops:  fonts 9 0 0 0 0 0 SS S ZD ZDR
gropdf: fonts 9 0 0 0 0 0 0 S ZD ZDR

which explains the font selection that occurred. I do not understand, however, 
while this ultimately
lead to _slanted_ glyphs with gropdf and _upright_ glyphs with grops (exactly 
the other way around
as I would have expected for S vs SS).

2.
forcing grops to also use S (by editing the DESC file and removing SS from the 
entry) leads to sane
ps and pdf output with both devices (no misalignment and strange irregular widths of the greek 
letters). so this would be the quick patch to "repair" grops: change the DESC file.

3.
using now the same font S, the glyphs produced by grops are upright (expected) 
and those produced
by gropdf are slanted (unexpected). why is that??

the main observation remains unaltered: in standard setup grops uses SS for typesetting greek 
letters since SS is found before S according to DESC and this leads to rather massive typesetting 
errors in equations using possibly many greek letters: cumulative mispositioning of stuff later on 
the same line.

what do to about this?

thank you
joerg


On 25.07.22 22:42, joerg van den hoff wrote:
> mmh, second try: I've send the below report 8h ago but it seems to not have made it through: there 
> are now several more recent messages in the archive. hopefully it succeeds this time:
>
>
> ==original message===
>
> I have compiled an old (>10 years) equation heavy troff ms-document and do see now issues, which I 
> believe (but cannot proof) where absent in the past.
>
> consider this example:
>
> .\"====================cut=================
> .\"groff -e -ms tt.trf > tt1.ps         -- broken output (output from ps2pdf 
> tt1.ps, too, of course)
> .\"groff -e -ms -Tpdf tt.trf > tt2.pdf  -- looks good.
> .\"----------------------------------------------------------------------------------------------
> .LP
> .EQ (1)
> alpha beta gamma delta rho sigma 1 over 2
> .EN
> .LP
> .EQ (2)
> a b c d r s 1 over 2
> .EN
> .\"====================cut=================
>
> the issues I see are:
>
> 1.
> in ps output from grops: heavily misalignment of numbers in the 1/2 ratio relative to the dividing 
> line when the ratio is preceded by greek symbols but not when preceded by standard characters.
> one also can note that there is extraneous and uneven white space between the greek letters (eqn 
> should typeset them w/o any white space I believe, basically treating all glyphs as "one word" just 
> as happened in Eq.2).
>
> 2.
> while gropdf output does _not_ have the above misalignment and extraneous whitespace issue, there is 
> a inconsistency relative to grops in so far as grops uses the Symbols font for the greek letters 
> (i.e. glyphs like \[*a]) while gropdf uses Symbols-Slanted.
>
> remarks:
>
> a)
> it seems to me that using the Symbols font like grops does (these days) is the 
> desirable behaviour
> and what gropdf does (using Symbols-Slanted) is not.
>
> b)
> I guess the misalignment of the 1/2 ratio with grops is caused by the mentioned white space between 
> (or wrong assumed width of?) the greek letters which cumulatively seems to influence where the 1 and
> the 2 in the ratio end up horizontally.
>
> c)
> no, I cannot simply switch to gropdf for that document (lots of ps-figures 
> included etc.) :)
>
> any ideas?
>
> joerg