[Pmwiki-users] Re: Math->image using LaTeX (was Re: More blue skye stuff...)
Christian Ridderström
chr
Thu Feb 5 12:31:26 CST 2004
On Thu, 5 Feb 2004, Patrick R. Michaud wrote:
> On Thu, Feb 05, 2004 at 01:26:35AM +0100, Christian Ridderstr?m wrote:
> > I have a mockup here:
> > http://www.lyx.org/~chr/wiki/pmwiki.php?pagename=Math.Math
> >
> > A statement such as [[$ e+f = \sqrt{r^2 - x^2} $]] invokes a function
> > called FmtMath() with 'e+f = \sqrt{r^2 - x^2}' as one of the arguments.
>
> I like the markup chosen here.
Is $ ... $ inline math or display math in Latex? (and what's the other?)
> > A practical feature What's probably missing is a cacheing system. Before
> > converting the latex, FmtMath() or the external script, should check if
> > this particular piece of latex has already been converted. OTOH, if we
> > cache these images we'll also need to do garbage collection so that the
> > size cache-directory doesn't increase arbitrarily.
>
> Easy: MD5 hash the string in brackets, and use that as the name of the
> (cached) file containing the output. Whenever a formula is encountered,
> perform an MD5 to determine the appropriate cache file to send. If the
> cache file doesn't exist, create it before sending.
>
> To keep the cache directory from overflowing, just remove it on a periodic
> basis and let the system recreate the (cache) files as needed.
I almost wrote something like "and the cache implementation is left as an
exercise for the interested reader" :-)
Btw, this is such a standard thing... isn't there a ready made package for
cacheing things like this?
But about the MD5 hash... what's the likelyhood of a false positive?
Don't we also need to maintain an exact copy of the latex code?
Hmm... I wonder if the .png file could contain this information in some
auxiliarly comment field?
/Christian
--
Christian Ridderstr?m http://www.md.kth.se/~chr
More information about the pmwiki-users
mailing list