Fix the names of a data frame containing an offset variable.

Removes evaluated offset columns while retaining their raw input variables. Raw inputs are recovered from fitting data if needed; transformed offset values are never renamed as raw values. A scalar offset_val overrides the raw input only for a single offset with one unambiguous input variable.

Usage

fix_offset(model, newdata, offset_val = NULL)

Arguments

model

a fitted GAM.

newdata

data frame; new values at which to predict at.

offset_val

numeric, optional; if provided, then the offset variable in newdata is set to this constant value before returning newdata

Value

The original newdata is returned with fixed names and possibly modified offset variable.

Author

Gavin L. Simpson

Examples

load_mgcv()
df <- data_sim("eg1", n = 400, dist = "normal", seed = 2)
m <- gam(y ~ s(x0) + s(x1) + offset(x2), data = df, method = "REML")
names(model.frame(m))
#> [1] "y"          "offset(x2)" "x0"         "x1"        
names(fix_offset(m, model.frame(m), offset_val = 1L))
#> [1] "y"  "x2" "x0" "x1"