This function generates a time trend for given time points in the trial according to a periodic function.
Usage
seasonal_trend(j, lambda, n_wave, n_total)
Arguments
- j
Time points for which the trend should be generated.
- lambda
Strength of time trend.
- n_wave
How many cycles (waves) should the time trend have (\(\psi\)).
- n_total
Total sample size in the trial.
Value
Time trend for time points j.
Details
The time trend is generated according to the function \(f(j) = \lambda \cdot \mathrm{sin} \big( \psi \cdot 2\pi \cdot \frac{j-1}{N-1} \big)\), where \(N\) is the total sample size (parameter n_total) and the parameter \(\psi\) corresponds to the input parameter n_wave.
Author
Marta Bofill Roig, Pavla Krotka