Goldstein D B, Kakihana R
Psychopharmacology (Berl). 1977 Mar 23;52(1):41-5. doi: 10.1007/BF00426598.
On the assumption that a sinusoidal curve adequately described the circadian rhythm of food or fluid consumption by mice, the whole daily pattern can be derived from a few observations. Examples are presented to show that the assumption is valid. This simple curve-fitting by computer is also applicable to analysis of blood levels of drugs administered in the food or drinking fluid. The method should be useful for estimating the magnitude of daily fluctuations in pharmacological variables, including drug intake rates and circulating drug levels.