atan arctangent
a.atan
atan(a)
atan(1);
1.atan;
atan(1) == 0.25pi; // true
atan(2000.1); // any value can be mapped into the range of -0.5pi .. 0.5pi by atan
(-100..100).atan.plot;
// atan is the reverse of sin:
atan(sin([-1, -0.5, 0, 0.5, 1]));
\foo.atan; // returns itself. this is used in Envelopes see Env.
f = atan({|x| sin(x) });
f.value((0..1000).normalize(1, 8)).plot;
(
{
var a;
a = Line.ar(0, 100, 0.01);
(a.atan / 0.25pi) - 1
}.plot
)