@Section
   @Title { Changing the overall appearance of the pie graph }
   @Tag { pie_over }
@Begin
@PP
We've already seen that all @Code "@Slice" options may be given
piegraphs. @RawIndex { pie graphs }
piegraphs.overall @SubIndex { overall appearance }
to @Code "@Pie" as well.  In addition to those, @Code "@Pie" has
its own options that affect the overall appearance of the pie graph:
@ID -1px @Break @OneRow @Code @Verbatim {
@Pie
    radius { 2.5c }
    initialangle { 0d }
    leftextra { 0c }
    rightextra { 0c }
    aboveextra { 0c }
    belowextra { 0c }
}
This example shows these options with their default values.
@PP
The @Code radius option determines the radius of the pie
radius. @RawIndex { @Code "radius" option }
radius.pie @SubIndex { in pie graphs }
piegraphs. @RawIndex { pie graphs }
piegraphs.radius @SubIndex { @Code "radius" option }
graph.  As shown, the default radius is 2.5 centimetres, giving a diameter
of 5 centimetres.
@PP
The @Code initialangle option determines the angle that the first
initialangle.pie @Index { @Code "initialangle" option (pie graphs) }
piegraphs. @RawIndex { pie graphs }
piegraphs.initialangle @SubIndex { @Code "initialangle" option }
slice begins at.  Following mathematical convention, the default angle
@Code 0d is directly to the right of the centre of the pie graph, and
as the value of @Code initialangle is increased the initial angle moves
anticlockwise.  The slices are placed in anticlockwise order immediately
adjacent to each other.  If you need a gap between two slices, use a
slice with no outline, no paint, and no label.
@PP
Lout thinks that the whole pie graph occupies a square space
tightly fitting around the given radius, as we can verify by
drawing a box with zero margin around an example pie graph:
@CD @Box margin { 0i } @Pie
{
    @Slice
        weight { 20 }
        label { Admin (20%) }
    @Slice
        weight { 40 }
        paint { green }
        label { Research (40%) }
    @Slice
        weight { 40 }
        paint { lightred }
        label { Teaching (40%) }
}
Detached slices (Section {@NumberOf pie_slic}) and external
labels (Section {@NumberOf pie_labe}) can be printed outside
this square region without Lout's knowledge, and this is
likely to spoil the layout:
@CD @Box margin { 0i } @Pie
{
    @Slice
	detach { yes }
        weight { 20 }
        label { Admin (20%) }
    @Slice
        weight { 40 }
        paint { green }
        label { Research (40%) }
    @Slice
        weight { 40 }
        paint { lightred }
        label { Teaching (40%) }
}
The {@Code leftextra}, {@Code rightextra}, {@Code aboveextra}, and
leftextra.pie @Index { @Code "leftextra" option (pie graphs) }
piegraphs. @RawIndex { pie graphs }
piegraphs.leftextra @SubIndex { @Code "leftextra" option }
rightextra.pie @Index { @Code "rightextra" option (pie graphs) }
piegraphs. @RawIndex { pie graphs }
piegraphs.rightextra @SubIndex { @Code "rightextra" option }
aboveextra.pie @Index { @Code "aboveextra" option (pie graphs) }
piegraphs. @RawIndex { pie graphs }
piegraphs.aboveextra @SubIndex { @Code "aboveextra" option }
belowextra.pie @Index { @Code "belowextra" option (pie graphs) }
piegraphs. @RawIndex { pie graphs }
piegraphs.belowextra @SubIndex { @Code "belowextra" option }
{@Code belowextra} options are used to tell Lout to leave extra
space to the left, right, above, and below, so as to correct these
problems:
@ID -1px @Break @OneRow @Code @Verbatim {
@Pie
    aboveextra { 0.7c }
}
We have not added extra space at the right as well, since we prefer
to centre the pie graph horizontally without regard to detached
slices.  The result occupies 0.7 cm extra at the top:
@CD @Box margin { 0i } @Pie aboveextra { 0.7c }
{
    @Slice
	detach { yes }
        weight { 20 }
        label { Admin (20%) }
    @Slice
        weight { 40 }
        paint { green }
        label { Research (40%) }
    @Slice
        weight { 40 }
        paint { lightred }
        label { Teaching (40%) }
}
We'll see these options again when we come to external labels in
Section {@NumberOf pie_labe}.
@End @Section