XLine

An exponential curve generator UGen that moves from a start value to the end value in a given duration.

At a given point in time 0 <= t <= dur , the output value is start * (stop/start).pow(t/dur) .

'''Warning''': It must be ensured that the both start is not zero and start and end have the same sign (e.g. a start of -1 and an end of -0.001 are valid), otherwise the UGen will output a NaN ! While in the case of end being zero the UGen will also output zero, it is recommended to treat this case as pathological as well.

===Examples===

// glissando
play { SinOsc.ar(Line.kr(200, 2000, 10, freeSelf)) * 0.2 }