Generate GAM formula with factor-smooth interaction
generator_gamFormula_factorXsmooth.RdThis function will generate a formula in the following format: y ~ orderedFactor + s(x) + s(x, by=orderedFactor),
where y is response.var, x is smooth.var, and orderedFactor is factor.var - see factor.var for more.
The formula generated could be further modified, e.g. adding covariates.
Usage
generator_gamFormula_factorXsmooth(
response.var,
factor.var,
smooth.var,
phenotypes,
reference.group = NULL,
prefix.ordered.factor = "o",
fx = TRUE,
k = NULL
)Arguments
- response.var
character class, the variable name for response
- factor.var
character class, the variable name for factor. It should be an ordered factor. If not, it will generate it as a new column in `phenotypes`, which requires `reference.group`.
- smooth.var
character class, the variable name in smooth term as main effect
- phenotypes
data.frame class, the cohort matrix with columns of independent variables (including
factor.varandsmooth.var) to be added to the model- reference.group
character class, the reference group for ordered factor of `factor.var`; required when `factor.var` in `phenotypes` is not an ordered factor.
- prefix.ordered.factor
character class, the prefix for ordered factor; required when `factor.var` in `phenotypes` is not an ordered factor.
- fx
TRUE or FALSE, to be used in smooth term s(). Recommend TRUE.
- k
integer, to be used in smooth term including the interaction term. If NULL (no entry), will use default value as in mgcv::s()