Creates the c_hat input for lgp, so that it accounts for normalization between data points in the "poisson" or "nb" observation model

adjusted_c_hat(y, norm_factors)

## Arguments

y response variable, vector of length n normalization factors, vector of length n

## Value

a vector of length n, which can be used as the c_hat input to the lgp function

Other data frame handling functions: add_dis_age(), add_factor_crossing(), add_factor(), new_x(), split()