Hey Martin, I agree about creating a booklet or sorts. How does everyone feel about using a website like Google Docs or something like that? Are there alternative document sharing sites like that out there?
Another thought would be to host it under the SIS user account on menataur or whatever the people.a.o sites are hosted on. What are your thoughts on that? http://people.apache.org/~sis Thanks, Adam On Tue, Jun 10, 2014 at 8:57 AM, Martin Desruisseaux <[email protected]> wrote: > Hello all > > We started to port the org.apache.sis.referencing.operation.transform > package recently. Conceptually, those "math transform" implementations > rely extensively on matrix for many kind of operations, including axis > flipping, unit conversions, etc. In the implementation details, some > classes use more straightforward code for performance reasons, but those > details are hidden from the API - conceptually, we have matrix pretty > much everywhere. > > Matrices are powerful, and it would be difficult to design a robust > Apache SIS without them. Inconvenient is that not every developer feel > comfortable with them, which may increase the entry barrier in the > sis-referencing and (upcoming) sis-coverage modules. In order to help > developers to get their hands in, I don't think that it would be a good > idea to avoid matrix usage - in my experience, "intuitive" replacements > have more limitations and sometime fuzzy behaviour. This leave us > documentation. > > A while ago I wrote a document for an OGC working group about how we > could handle "axis swapping". I don't think that the proposal had been > adopted, so all the discussion about Web Map Server (WMS) can be > ignored. However the mathematical discussion is still valid: > > http://people.apache.org/~desruisseaux/discussion/AxisFlip.pdf > > The above is about one specific matrix usage - there is more to said in > other aspects. My concern is: can we structure this kind of information > in some Apache SIS document? Not just a copy-and-paste of the above, but > some well structured document. Maybe something like my "book" attempt, > but in English. Would we have a volunteer for such work? This document > would not be that much about Apache SIS classes, but rather about the > mathematical concepts that we use in SIS, like the mathematical parts in > the above document. > > About where to put such document: I'm not a big fan of wiki... I think > wiki is fine for small drafts, but I'm not sure it is suitable for a > "book". Furthermore, our documentation is likely to have many matrix and > mathematical equations. I would feel more attracted by "HTML + MathML" > or "Docbook + MathML", or maybe epub if it allows MathML (but I do not > know epub enough). > > I would like to know what peoples think? > > Martin >
