gbmcv_bin(df, bad, tot_derog)
### OUTPUT ###
# $df
#   bin                           rule freq   dist mv_cnt bad_freq bad_rate     woe     iv      ks
#    00                      is.na($X)  213 0.0365    213       70   0.3286  0.6416 0.0178  2.7716
#    01                        $X <= 1 3741 0.6409      0      560   0.1497 -0.3811 0.0828 18.9469
#    02               $X > 1 & $X <= 2  478 0.0819      0      121   0.2531  0.2740 0.0066 16.5222
#    03                         $X > 2 1405 0.2407      0      445   0.3167  0.5871 0.0970  0.0000
# $cuts
# [1] 1 2