Mixed effect model formula parser
Parses a mixed effect model in the lme4 structure of ~fixed +(re1|g1) +...+(ren|gn)
proc.form(f)
A list with elements fix.model and re.model. fix.model contains the formula for the fixed effects; re.model contains elements sub, the grouping formula and model the design formula for the random effect. Each formula is of type character and must be wrapped with as.formula in use with model.matrix
formula for mixed effect mode in the form used in lme4; ~fixed +(re1|g1) +...+(ren|gn)
Devin Johnson <devin.johnson@noaa.gov>