Plot placement, revisited

[Daniel J S. <dan...@ie...>]

If you recall, there was a discussion of precisely controlling the size 
of a plot.  It concerned how labels would take away space from the plot 
so that the eventual size of the borders was random, or at least not 
known to the user.  The solution was to set the margins to 0, for which 
the values specified in "size" matched the borders of the plot.  That 
worked fine.

But there is a similar situation with the key.  When the key is 
specified as "below", that uses up space, so again "set size X,Y" is no 
longer the precise size of the borders.  There is an option for 
specifying the location of the key, "set key x,y", which does not use up 
space.  That would work, but unfortunately there seems no way to 
independently control "maximize number of columns" vs. "maximize number 
of rows".  Instead, here is the control structure within the code:

    if (key->flag == KEY_AUTO_PLACEMENT) {
        if (key->vpos == TUNDER) {
            /* maximise no cols, limited by label-length */
        } else {
            /* maximise no rows, limited by ytop-ybot */
        }
    }

It would be nice to be able to control the "max no cols" vs. "max no 
row" independent of the autoplacement.  As it stands, there is no 
"above" autoplacement, only "below";  and there is the using up space 
issue I've mentioned.

Depending upon the interior lines of the plot, someone might even want 
to have a "maximize no cols" and place it somewhere within the borders. 
 So, I would argue for making these independent.  That is, perhaps a 
"maxcols"/"maxrows" key word.  Imagine there were independent keywords

right, left, center, bottom, top
maxcols, maxrows
inside, outside

The first set of keywords would control the 9 possible "default" locations.

1 2 3
4 5 6
7 8 9

1 - left top
2 - top center
3 - top right
4 - left center
5 - center
6 - right center
7 - bottom left
8 - center bottom
9 - right bottom

(#5 seems like a goofy choice, but so be it.)

Also, the same combinations make sense no matter if you say 
independently "outside" versuse "inside".  Same for "maxcols" vs. "maxrows".

Then, in one sense, the current keywords "outside" and "below" actually 
have multiple meaning.  "outside" really means "outside, right/center, 
maxrows"; "below" really means "outside, bottom/center, maxcols".

Dan