Creates a character string expression to calculate the predicted values
Given the covariates and the name of the coefficients corresponding to a given cluster, the function construct a character string, which will be used to calculate the predicted values.
Name of the covariates.
Name of the coefficients.
Name of the glm model.
To calculate the predicted values in each cluster, we
need the values of the covariates in the data and the
right coefficients in the 'glm' object. To do this we
construct an expression which will be evaluated inside
A character string of the expression of the predicted values of a given cluster.
Meant to be used internally.