apply_acd               Function to apply Approximate Cumulative
                        Distribution (ACD)
apply_shift_scale       Shift and scale vector x
art                     Artificial dataset with continuous response
assign_df               Helper to assign degrees of freedom
backscale_matrix        Backscale Columns of a Matrix (Internal)
calculate_df            Helper to calculates the final degrees of
                        freedom for the selected model
calculate_f_test        Function to compute F-statistic and p-value
                        from deviances
calculate_lr_test       Function to calculate p-values for
                        likelihood-ratio test
calculate_model_metrics
                        Function to compute model metrics to be used
                        within 'mfp2'
calculate_number_fp_powers
                        Calculates the total number of fractional
                        polynomial powers in adjustment variables.
calculate_standard_error
                        Helper function to compute standard error of a
                        partial predictor
center_matrix           Simple function to center data
coef.mfp2               Extract coefficients from object of class
                        'mfp2'
convert_powers_list_to_matrix
                        Helper to convert a nested list with same or
                        different length into a matrix
create_dummy_variables
                        Simple function to create dummy variables for
                        ordinal and nominal variables
create_fp_terms         Helper to create overview table of fp terms
deviance_gaussian       Deviance computations as used in mfp in stata
ensure_length           Helper function to ensure vectors have a
                        specified length
find_best_fp1_for_acd   Function to fit univariable FP1 models for acd
                        transformation
find_best_fp_cycle      Helper to run cycles of the mfp algorithm
find_best_fp_step       Function to estimate the best FP functions for
                        a single variable
find_best_fpm_step      Function to find the best FP functions of given
                        degree for a single variable
find_scale_factor       Function that calculates an integer used to
                        scale predictor
find_shift_factor       Function that calculates a value used to shift
                        predictor
fit_acd                 Function to estimate approximate cumulative
                        distribution (ACD)
fit_cox                 Function that fits Cox proportional hazards
                        models
fit_glm                 Function that fits generalized linear models
fit_linear_step         Function to fit linear model for variable of
                        interest
fit_mfp                 Function for fitting a model using the MFP or
                        MFPA algorithm
fit_model               Function that fits models supported by 'mfp2'
fit_null_step           Function to fit null model excluding variable
                        of interest
fp                      Helper to assign attributes to a variable
                        undergoing FP-transformation
fracplot                Plot response functions from a fitted 'mfp2'
                        object
gbsg                    Breast cancer dataset used in the Royston and
                        Sauerbrei (2008) book.
generate_combinations_with_replacement
                        Helper function to generate combinations with
                        replacement
generate_powers_fp      Function that generates a matrix of FP powers
                        for any degree
generate_transformations_fp
                        Function to generate all requested FP
                        transformations for a single variable
get_selected_variable_names
                        Helper function to extract selected variables
                        from fitted 'mfp2' object
mfp2                    Multivariable Fractional Polynomial Models with
                        Extensions
name_transformed_variables
                        Helper function to name transformed variables
order_variables         Helper to order variables for mfp2 algorithm
pima                    Pima Indians dataset used in the Royston and
                        Sauerbrei (2008) book.
predict.mfp2            Predict Method for 'mfp2'
prepare_newdata_for_predict
                        Helper function to prepare newdata for predict
                        function
print.mfp2              Print method for objects of class 'mfp2'
print_mfp_step          Function for verbose printing of function
                        selection procedure (FSP)
prostate                Prostate cancer dataset used in the Royston and
                        Sauerbrei (2008) book.
reset_acd               Helper to reset acd transformation for
                        variables with few values
select_ic               Function selection procedure based on
                        information criteria
select_linear           Helper to select between null and linear term
                        for a single variable
select_ra2              Function selection procedure based on closed
                        testing procedure
select_ra2_acd          Function selection procedure for ACD based on
                        closed testing procedure
summary.mfp2            Summarizing 'mfp2' model fits
transform_data_step     Function to extract and transform adjustment
                        variables
transform_matrix        Function to transform each column of matrix
                        using final FP powers or acd
transform_vector_fp     Functions to transform a variable using
                        fractional polynomial powers or acd
transform_vector_power
                        Simple function to transform vector by a single
                        power
