On Wed, Nov 03, 2010 at 12:56:40AM -0700, Alan Irwin wrote: > Hi Hez: > > I have made some additional progress with pllegend as of revision 11304. > > 4. (after further discussion with you). > > >> I think it is worth considering different ways of expressing the > >> position of a legend or color bar. For example, in the OCaml color > >> bar API, the position of the color bar is specified relative to a > >> user-specified plot subpage boundary. This could be done in the C API > >> with another set of options for the "opt" parameter: PL_LEGEND_TOP, > >> PL_LEGEND_BOTTOM, PL_LEGEND_LEFT, PL_LEGEND_RIGHT and possibly > >> PL_LEGEND_CENTER. The position arguments would then be interpreted as > >> offsets from the given side. For example: > >> > >> PL_LEGEND_BOTTOM | PL_LEGEND_RIGHT : Position the box relative to the > >> bottom-right of the plot subpage > >> > >> PL_LEGEND_RIGHT | PL_LEGEND_CENTER : Position the box relative to the > >> right side of the plot subpage, centered vertically (the y-position > >> would be ignored in this case) > >> > >> The default would continue to be PL_LEGEND_TOP | PL_LEGEND_LEFT. I > >> expect PL_LEGEND_CENTER to be more commonly used with plcolorbar. > > The QSAS team uses a number of fixed legend positions e.g., "inside top > right" would place the top right corner of the legend coincident with > the top right corner of the viewport while "inside bottom left" would > place the bottom left corner of the legend coincident with the bottom > left of the viewport. They also have "inside top left", "inside > bottom right", "above top centre", and "outside top right". I am not > exactly sure of the exact definition/usefulness of the last two. They > also allow a customized position like we have now. > > I think I prefer the QSAS legend position ideas over your idea above > of changing the origin of the custom coordinates. The fixed positions > will be useful, and it is more straightforward for users to have a > consistent origin for the customized positions (especially when the > values at the edges of the viewport are either 0. or 1.). However, it > is important to come to consensus about this since we want the same > position options for your plcolorbar so I look forward to your > response to the QSAS legend position ideas.
Gnuplot also use a similar generic positioning for legends (i.e. top left) which works well in my experience. They also provide for fine-grained positioning by setting the coordinates of the legend (in plot coordinates). I think this approach works well. 95% of the time the general approach is sufficient, and means things work even if the axes etc change, however I do find the fine-grained control necessary on occasions to minimise interference between the plot and the legend. I agree with Alan, that fixed positions for the custom origin are better. You can argue whether you want them in relative coordinates (i.e. 0-1) or in the current axis coordinates. Probably relative I think, although there are arguments each way. Andrew ------------------------------------------------------------------------------ The Next 800 Companies to Lead America's Growth: New Video Whitepaper David G. Thomson, author of the best-selling book "Blueprint to a Billion" shares his insights and actions to help propel your business during the next growth cycle. Listen Now! http://p.sf.net/sfu/SAP-dev2dev _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
