Hello, Stefan!

I need to plot the three biorhythm curves.

The curves start at your birthday, following a sine waveform and have following periods:

emotional curve 28 days, physical curve 23 days and intellectual 33 days.

I need to plot any ones curves for any interval, given the person's birthdate,

startdate for the interval and length of the interval.

The basic curves are: .

. . where is the number of days since the person's birth.

You will need a separate algorithm to calculate

. . for any birthdate and any start-date for the interval.