cosinor.lm {cosinor} | R Documentation |
Fit cosinor model
Description
Given an outcome and time variable, fit the cosinor model with optional covariate effects.
Usage
cosinor.lm(formula, period = 12, data, na.action = na.omit)
Arguments
formula |
Formula specifying the model. Indicate the time variable with
|
period |
Length of time for a complete period of the sine curve. |
data |
Data frame where variable can be found |
na.action |
What to do with missing data |
Details
This defines special functions that are used in the formula to
indicate the time variable and which covariates effect the amplitude. To
indicate the time variable wrap the name of it in the function
time()
. To indicate a variable which affects the
acrophase/amplitude, wrap the name in amp.acro()
. This will then do
all the transformations for you. See examples for usage.
References
Tong, YL. Parameter Estimation in Studying Circadian Rhythms, Biometrics (1976). 32(1):85–94.
Examples
cosinor.lm(Y ~ time(time) + X + amp.acro(X), data = vitamind)