Returns the design matrix for a general k-phase intervention model
Usage
hmmat(vecss, k)
Arguments
vecss
a vector of length k with each element being the number of observations in each phase
k
number of phases
Details
It returns a matrix of 2*k columns. The design can be unbalanced, i.e. each phase has different observations.
References
Huitema, B. E., Mckean, J. W., & Mcknight, S. (1999). Autocorrelation effects on least-
squares intervention analysis of short time series. Educational and Psychological
Measurement, 59 (5), 767-786.