I ran the following code to centering the variables.But is comes one error. Please let me know how can I solve the problem. Thanks in advance.
grfc <- glm(VCPI ~ (drf$State_owned-0.4168) + Time + Time * State_owned + EC + (drf$Leverage-0.6596) +log(Size)+ (drf$ROA-0.020705)*Industry, data = drf, family = "binomial")
Error in terms.formula(formula, data = data) :
invalid model formula in ExtractVars