Biorythm.
The theory of biorythm is based on the assumption that in a person's life, there are three cycles which all start at the day of birth: 1. The fysical cycle - of 23 days. 2. The emotional cycle - of 28 days. 3. The intellectual cycle - of 33 days. Each first half of a cycle is supposed to contain the "better days", each second half is supposed to contain the "worse days". The amplitudes of these cycles can be expressed as a value between -10 and +10. This program shows the amplitudes over a periode of one month.