3.24.30.1 key placement
To understand positioning, the best concept is to think of a region, i.e.,
inside/outside, or one of the margins. Along with the region, keywords
‘left/center/right‘ (l/c/r) and ‘top/center/bottom‘ (t/c/b) control where
within the particular region the key should be placed.
When in ‘inside‘ mode, the keywords ‘left‘ (l), ‘right‘ (r), ‘top‘ (t),
‘bottom‘ (b), and ‘center‘ (c) push the key out toward the plot boundary as
illustrated:
When in ‘outside‘ mode, automatic placement is similar to the above
illustration, but with respect to the view, rather than the graph boundary.
That is, a border is moved inward to make room for the key outside of
the plotting area, although this may interfere with other labels and may
cause an error on some devices. The particular plot border that is moved
depends upon the position described above and the stacking direction. For
options centered in one of the dimensions, there is no ambiguity about which
border to move. For the corners, when the stack direction is ‘vertical‘, the
left or right border is moved inward appropriately. When the stack direction
is ‘horizontal‘, the top or bottom border is moved inward appropriately.
The margin syntax allows automatic placement of key regardless of stack
direction. When one of the margins lmargin (lm), rmargin (rm),
tmargin (tm), and bmargin (bm) is combined with a single, non-conflicting
direction keyword, the following illustrated positions may contain the key:
Keywords ‘above‘ and ‘over‘ are synonymous with tmargin. For version
compatibility, ‘above‘ or ‘over‘ without an additional l/c/r or stack direction
keyword uses ‘center‘ and ‘horizontal‘. Keywords ‘below‘ and ‘under‘ are
synonymous with bmargin. For compatibility, ‘below‘ or ‘under‘ without an
additional l/c/r or stack direction keyword uses ‘center‘ and ‘horizontal‘. A
further compatibility issue is that ‘outside‘ appearing without an additional
t/b/c or stack direction keyword uses ‘top‘, ‘right‘ and ‘vertical‘ (i.e., the
same as t/rm above).
The <position> can be a simple x,y,z as in previous versions, but these can
be preceded by one of five keywords (‘first‘, ‘second‘, ‘graph‘, ‘screen‘,
‘character‘) which selects the coordinate system in which the position of
the first sample line is specified. See ‘coordinates‘ for more details.
The effect of ‘left‘, ‘right‘, ‘top‘, ‘bottom‘, and ‘center‘ when <position>
is given is to align the key as though it were text positioned using the
label command, i.e., ‘left‘ means left align with key to the right of
<position>, etc.