Find the needle of an am5radar gauge, or null for any other chart.
The signature is deliberately narrow, because a RadarChart is also what a
radar and a polar area are drawn in: the class name has to match and an
axis has to carry a ClockHand. The caller adds the third condition — this
is asked only of a chart whose series produced no layer at all — so an
ordinary radar chart never reaches it even if someone pins a hand to one.
A chart with several hands is read as its first, with a warning: MAIDR's
gauge is one measure against one range, and there is no shape here for a
second.
Find the needle of an am5radar gauge, or
nullfor any other chart.The signature is deliberately narrow, because a
RadarChartis also what a radar and a polar area are drawn in: the class name has to match and an axis has to carry aClockHand. The caller adds the third condition — this is asked only of a chart whose series produced no layer at all — so an ordinary radar chart never reaches it even if someone pins a hand to one.A chart with several hands is read as its first, with a warning: MAIDR's gauge is one measure against one range, and there is no shape here for a second.