On Fri, Oct 10, 2008 at 12:09 AM, Maurice LeBrun <[EMAIL PROTECTED]> wrote: > > What do you think of this as a compromise? Nothing has to be > > propagated to other language bindings, and the plgvpw functionality > > becomes (I think) more intuitive. > > I have to admit to being a little bothered by this change. The plP_gvpw > private function is a good way to shield internal workings from this change, > but begs the larger question: what should plgvpw() actually return? I can see > three classes of opinion on the topic: > > 1. plgvpw() MUST return exactly what I specified in plwind() > 2. plgvpw() MUST return exactly what the plot library's actually using > 3. either is "good enough" > > There are good arguments for both 1 & 2. (2) is what we're using now, moving > to (1) is the proposal. The people in category (1) could reverse the delta > easily enough, as long as it was documented & didn't change. The people in > category (2) could do the same, on old code that's long since been forgotten > about. The vast majority in (3) will never notice. > > As a user, I'm in category (3), and don't *really* care either way. But be > aware you are introducing a change that has the potential to change existing > code behavior.
Maurice, Thank you for your feedback on this. My extra argument for position (1) is that, for some viewport dimensions, the delta is not cleanly reversible due to floating point rounding errors. Adding the delta to get the (2) case does not have this floating point rounding problem so the values for (2) are always retrievable if the values from (1) are still available. The proposal is certainly a change to plgvpw's prior behavior. But being able to retrieve the case (1) information from PLplot is, I think, quite important as it relieves the user from having to track this information which leaves less for the user to keep track of on their own, and hopefully less room for user error. It will also make adding new PLplot-related functions (such as legends or interactions with external Cairo surfaces) much cleaner since these functions can retrieve the user-provided information directly from PLplot. If it is too close to the 5.9.1 release to consider a change like this, perhaps it could be reconsidered after 5.9.1 is released? Thank you again for taking the time to comment on this. Hez -- Hezekiah M. Carty Graduate Research Assistant University of Maryland Department of Atmospheric and Oceanic Science ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
