On Thu, Jan 10, 2008 at 09:57:18PM +0100, Gunnar Ritter wrote: > Joerg van den Hoff <[EMAIL PROTECTED]> wrote: > > > shows that the "hat" is sort of right aligned above the K, > > not centered as the dot is in the ps output. moreover the > > vertical distance above the K seems different for both marks > > (probably they both are "top aligned" in this direction?). > > Thanks. A fix is in the CVS repository. > > > what's more: the default spacing used by `eqn' (i.e. the > > spacing used without introducing explicit white space, e.g. > > with the `^' command) is markedly different between groff > > and "htroff" eqn. in htroff there seems actually no > > additional white space whatever in the above equations, > > e.g.. this simply does not look right. I confess not having > > thoroughly looked whether this spacing is somewhere > > adjustable via registers (maybe it is), but if so, the > > default value at least is not a good one. > > It seems that this has been a deliberate decision with the > original eqn since its user's guide explicitly states that > you should use "~" to get more space with equations. When > this document is formatted with geqn, the output looks the > same with and without the "~", so the remark would make no > sense with it.
I don't think so. look at http://cm.bell-labs.com/cm/cs/papers.html where there is a ps version of the original eqn users guide (first entry in the list). the postscript header indicates that this was generated by some `dpost' implementation. if you look, e.g. at the small equation (3.1a) on the second page and write this down without any explicit space and alternatively with explicit spaces: .EQ lpile { x = f(y/2) + y/2 above x ~ = ~ f(y/2) ~ + ~ y ~ / ~ 2 } .EN and compare "geqn/groff" with "heqn/htroff" generated ps output _and_ with the above document from bell labs you'll see especially that in the original doc the equation is typeset with _some_ spacing, different from groff but more (and better) spacing than by heqn/htroff. > > In general, geqn goes more into the direction of TeX and > tries to more automatically layout the formulas, whereas > the old eqn on which Heirloom eqn is based requires manual > interaction in many places. However, documents on which > such hand-tuning is applied would not get formatted as > intended if Heirloom eqn did the same. Thus, I will keep > it as is; I also regard it as a good thing if the two > programs keep a different approach to formula typesetting. the latter is fine with me (although I don't think that geqn is much more "automatic" than the original one). my point is that `eqn' should always by default produce visually pleasing/acceptable output. the manual rather clearly states that using additional explicit spacing means "tweaking". one should not need to do this _always_. so my main point is: it seem's that the "ancient" kernighan eqn manual shows that `eqn' produces sufficient spacing in it's output without providing explicit "~" or "^" directives and heqn does'nt do this. (at least not everywhere: e.g. in "f(y/2)" in the above example heqn puts more space between "f" and "(" than geqn.) > > > and unfortenuately both eqn preprocessors are not > > interchangable. another question would be: could the output > > be made compatible (it should be, if `groff' did not do > > groff-specific things in the troff commands emitted by eqn, > > right?) > > It is generally no problem to use geqn with Heirloom troff; > there is not even a need to turn groff compatibility mode on. > The one thing which I know not to work is the placement of > the parts of large brackets and parentheses. The reason for > this is that Heirloom dpost (not my idea, but part of the > original dpost design) tunes the glyph placement of the > PostScript Symbol font to work with unmodified original eqn > output. This gets in the way when geqn expects the glyphs > to be positioned as with the standard Symbol font. seem's not to be true if I don't do something silly wrong. with the above example formula (say in file "tt") and geqn tt | groff -ms > tt.ps heqn tt | htroff -ms | dpost > tt2.ps geqn tt | htroff -ms | dpost > tt3.ps only the first two work. the third produces an empty page when viewed in `gv'. joerg PS: and if werner is reading this: geqn seems to ignore part of explicit provided spaces "~" in the above example (it seems to be the default spacing anyway). is this intended behaviour: "increase spacing only by the difference of explicit provided space and default space"?
