On Fri, Dec 12, 2008 at 2:22 PM, Michael Droettboom <md...@stsci.edu> wrote:
> Darren Dale wrote:
>
>> On Fri, Dec 12, 2008 at 1:06 PM, Michael Droettboom <md...@stsci.edu<mailto:
>> md...@stsci.edu>> wrote:
>>
>> Darren Dale wrote:
>>
>> On Fri, Dec 12, 2008 at 9:46 AM, Michael Droettboom
>> <md...@stsci.edu <mailto:md...@stsci.edu>
>> <mailto:md...@stsci.edu <mailto:md...@stsci.edu>>> wrote:
>>
>> Manuel Metz wrote:
>> > Michael Droettboom wrote:
>> >
>> >> There was a discussion on this list around a year ago about
>> this. The
>> >> concern was that not rendering $ as $ would break
>> (matplotlib)
>> backward
>> >> compatibility with scripts that don't care about math at all
>> but use a
>> >> lot of dollar signs (e.g. financial plots). This is one
>> of the few
>> >> places where we deliberately broke usetex compatibility in
>> favour of
>> >> matplotlib compatibility.
>> >>
>> >> That said, it's probably a bug that the escaped dollar
>> sign in
>> non-math
>> >> context is not rendered as a dollar sign.
>> >>
>> >> As a workaround "$\$%1.2f$" works with usetex on or off,
>> with the
>> >> proviso that it uses math- rather than text-rendering
>> for the
>> numbers.
>> >>
>> >> Mike
>> >>
>> >
>> > In that case I suggest to note this somewhere in the docs
>> (and User
>> > Guide) with three exclamation marks (or is it ???).
>> >
>> So there's really two sub-bugs here:
>>
>> 1) '\$8' gives '\$8' in mathtext (well, actually it gets
>> sent verbatim
>> to the non-math text renderer, which is a bug). This,
>> IMHO, is a
>> "must-fix".
>>
>> 2) '$8' gives '$8' in mathtext and an error in usetex.
>> This could be
>> solved in two ways:
>>
>> a) document the difference
>> b) make '$8' give '$8' in usetex as well
>>
>> I realise b) is technically making usetex accept a string
>> that is not
>> normally valid TeX -- but it's not like a user would ever enter
>> '$8' and
>> *want* to get a TeX error back. And usetex strings aren't
>> perfectly TeX
>> anyway.
>>
>> Personally, I'm leaning toward b), because it requires less
>> mental
>> effort for the user turning usetex on/off. And it doesn't
>> force us to
>> backtrack on the idea of supporting "$100.00" easily.
>>
>> But before I commit -- any feedback?
>>
>> I opposed to b). If we go that route, we can look forward to
>> advertising usetex as "a latex backend, with familiar,
>> standard latex markup, except when it isnt."
>>
>> It's not as bad as that. '\$8' will still work as in LaTeX as it
>> always has and as a LaTeX expert would expect it to. All I'm
>> proposing is that '$8', which is currently a LaTeX syntax error,
>> will behave as it does when usetex is turned off. So it's not
>> breaking anything that's already valid.
>>
>> It's a question of which pain is worse, I guess.
>>
>> The deeper question is -- should usetex even strive to have any
>> compatibility with standard text? If not, then I can see your point.
>>
>>
>> http://matplotlib.sourceforge.net/users/mathtext.html advertises \$ as
>> markup for $.
>>
> That's always worked and still worked -- that's not the bug at hand.
>
>> I think it was unwise to accept $ for $ in mathtext in the first place,
>> since mathtext uses tex markup anyway.
>>
> I'm not proposing that at all. I think we're running into a
> misunderstanding about what I mean by "mathtext" and the scope of the
> proposed change. By mathtext, I mean "the text between a pair of $ $ when
> usetex is off". mathtext aims to be TeX-compatible (for a subset). Regular
> text does not (and in fact has no markup whatsoever). That last point, I
> believe, is the root of this problem and why reconciling usetex with
> non-usetex may be a losing battle, as you're starting to convince me.
> usetex is simply not the same thing as regular matplotlib text.
>
> I'll clarify anyway -- but I'm starting to think that unless there is
> someone doing financial plots with usetex that is dying for this feature,
> I'll just leave it.
>
> The bug at hand deals with regular text, not math text. There has been a
> test in the non-usetex code path for a long time to determine if there is
> any math in the string (by looking for an even number of non-escaped $) and
> allow the simple monetary case to work without needing to escape the $.
Right. I'm not criticizing the work you did on mathtext, which I think is
amazing and could not have done myself. And I forgot that because mathtext
used to be an all-or-nothing enterprise, there was no reason to escape the $
in regular text. Once you made it possible to embed mathtext in a regular
string, I think it would have been better in the long run to require \$, but
the powerful financial interests and their fat-cat lobbyists won the day.
> It used to be impossible to interleave math and regular text in the same
> string and I needed a way to add support for interleaving without breaking
> existing usage, and without requiring an explicit flag saying "my string has
> math". It's not perfect -- if you want to have math *and* use a dollar
> sign, you still have to know what you're doing and do some sort of escaping.
> But it's served well for over a year.
>
Thanks for reminding me, I forgot the context.
>
> The question, then, is whether to bring those smarts over to usetex, and
> whether any sort of usetex/non-usetex consistency is a goal.
>
>>
>> If we went with b), how sure are you that you can identify when a dollar
>> sign is intended and when mathmode is intended? Does "$A-$100+B*$200$" mean
>> $(A-100+200B) or A-100+200 or ..., I know this is an unlikely example, I'm
>> just trying to think of the unintended consequences of circumventing one of
>> the least buggy pieces of software in existence (I mean tex, not latex).
>>
>> It means [A-]100+B*[200] (where the contents in brackets is math,
> otherwise text), just like in TeX. An example where there is ambiguity is
> when you have an odd number, such as "$A-$100+B$". In TeX, that's a syntax
> error, but with my proposed change (and in non-usetex already) it would
> render as "$A-$100+B$". So at best, it's a "does the right thing", and at
> worst is a "silent fail", depending on your perspective.
>
> Hope that clears things up.
>
What I would prefer is to raise a deprecation warning when an odd number of
dollar signs are encountered, giving people time to learn to escape their $
and modify their code. I wonder how disruptive this would be to people using
mpl for finance? If that is unacceptable, I guess the best solution is as
you propose, but maybe usetex should issue a warning that it has modified
the string rather than strictly interpret it.
Do you know if there are any other inconsistencies between the text/mathtext
markup and latex?
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