 MTB > read 'a:\ed257\nwkt12p1.dat' c1 -c6
     54 ROWS READ

 ROW     C1    C2     C3     C4     C5        C6

   1    6.7    62     81   2.59    200   2.30103
   2    5.1    59     66   1.70    101   2.00432
   3    7.4    57     83   2.16    204   2.30963
   4    6.5    73     41   2.01    101   2.00432
  .  .  .

MTB > print c1-c6

 ROW     C1    C2     C3     C4     C5        C6

   1    6.7    62     81   2.59    200   2.30103
   2    5.1    59     66   1.70    101   2.00432
   3    7.4    57     83   2.16    204   2.30963
   4    6.5    73     41   2.01    101   2.00432
   5    7.8    65    115   4.30    509   2.70672
   6    5.8    38     72   1.42     80   1.90309
   7    5.7    46     63   1.91     80   1.90309
   8    3.7    68     81   2.57    127   2.10380
   9    6.0    67     93   2.50    202   2.30535
  10    3.7    76     94   2.40    203   2.30750
  11    6.3    84     83   4.13    329   2.51720
  12    6.7    51     43   1.86     65   1.81291
  13    5.8    96    114   3.95    830   2.91908
  14    5.8    83     88   3.95    330   2.51851
  15    7.7    62     67   3.40    168   2.22531
  16    7.4    74     68   2.40    217   2.33646
  17    6.0    85     28   2.98     87   1.93952
  18    3.7    51     41   1.55     34   1.53148
  19    7.3    68     74   3.56    215   2.33244
  20    5.6    57     87   3.02    172   2.23553
  21    5.2    52     76   2.85    109   2.03743
  22    3.4    83     53   1.12    136   2.13354
  23    6.7    26     68   2.10     70   1.84510
  24    5.8    67     86   3.40    220   2.34242
  25    6.3    59    100   2.95    276   2.44091
  26    5.8    61     73   3.50    144   2.15836
  27    5.2    52     86   2.45    181   2.25768
  28   11.2    76     90   5.59    574   2.75891
  29    5.2    54     56   2.71     72   1.85733
  30    5.8    76     59   2.58    178   2.25042
  31    3.2    64     65   0.74     71   1.85126
  32    8.7    45     23   2.52     58   1.76343
  33    5.0    59     73   3.50    116   2.06446
  34    5.8    72     93   3.30    295   2.46982
  35    5.4    58     70   2.64    115   2.06070
  36    5.3    51     99   2.60    184   2.26482
  37    2.6    74     86   2.05    118   2.07188
  38    4.3     8    119   2.85    120   2.07918
  39    4.8    61     76   2.45    151   2.17898
  40    5.4    52     88   1.81    148   2.17026
  41    5.2    49     72   1.84     95   1.97772
  42    3.6    28     99   1.30     75   1.87506
  43    8.8    86     88   6.40    483   2.68395
  44    6.5    56     77   2.85    153   2.18469
  45    3.4    77     93   1.48    191   2.28103
  46    6.5    40     84   3.00    123   2.08991
  47    4.5    73    106   3.05    311   2.49276
  48    4.8    86    101   4.10    398   2.59988
  49    5.1    67     77   2.86    158   2.19866
  50    3.9    82    103   4.55    310   2.49136
  51    6.6    77     46   1.95    124   2.09342
  52    6.4    85     40   1.21    125   2.09691
  53    6.4    59     85   2.33    198   2.29667
  54    8.8    78     72   3.20    313   2.49554

MTB > describe c1-c6

                N     MEAN   MEDIAN   TRMEAN    STDEV   SEMEAN
C1             54    5.783    5.800    5.715    1.603    0.218
C2             54    63.24    63.00    64.27    16.90     2.30
C3             54    77.11    79.00    77.60    21.25     2.89
C4             54    2.744    2.595    2.679    1.070    0.146
C5             54    197.2    155.5    178.7    145.3     19.8
C6             54   2.2061   2.1917   2.2008   0.2738   0.0373

              MIN      MAX       Q1       Q3
C1          2.600   11.200    4.950    6.525
C2           8.00    96.00    52.00    76.00
C3          23.00   119.00    66.75    90.75
C4          0.740    6.400    1.995    3.325
C5           34.0    830.0    107.0    217.7
C6         1.5315   2.9191   2.0292   2.3380

MTB > name c1='clotting' c2='prognost' c3='enzyme' c4='liver'
MTB > name c5='stime' c6='logstime'
MTB > stepwise 'logstime' on 'clotting' 'prognost' 'enzyme' 'liver';
SUBC>fenter=4.0;
SUBC>fremove=3.9.

**note: this is a forward stepwise NWK 453-4  *****************************
**matches exactly BMDP2R output NWK Fig 12.8 ***************************
 STEPWISE REGRESSION OF logstime ON  4 PREDICTORS, WITH N =   54

    STEP        1        2        3        4        5
CONSTANT   1.6964   1.3888   0.9423   0.4887   0.4836

liver      0.1858   0.1390   0.0818   0.0019
T-RATIO      7.62     6.30     5.46     0.20

enzyme             0.00565  0.00700  0.00947  0.00952
T-RATIO               5.09     9.98    23.91    31.08

prognost                    0.00790  0.00925  0.00929
T-RATIO                        9.16    21.19    24.30

clotting                              0.0685   0.0692
T-RATIO                                12.60    16.97

S           0.190    0.156   0.0965   0.0473   0.0469
R-SQ        52.74    68.65    88.29    97.24    97.23
 MORE? (YES, NO, SUBCOMMAND, OR HELP)
SUBC>y

 NO VARIABLES ENTERED OR REMOVED

 MORE? (YES, NO, SUBCOMMAND, OR HELP)
SUBC>n

***note:pure Forward Selection NWK p.458; MTBver7 p. 7-16;
MTB > stepwise 'logstime' on 'clotting' 'prognost' 'enzyme' 'liver';
SUBC>fenter=1;
SUBC>fremove=0.
***pure forward selection--NWK p458; MTBver7 7-16
 STEPWISE REGRESSION OF logstime ON  4 PREDICTORS, WITH N =   54

    STEP        1        2        3        4
CONSTANT   1.6964   1.3888   0.9423   0.4887

liver      0.1858   0.1390   0.0818   0.0019
T-RATIO      7.62     6.30     5.46     0.20

enzyme             0.00565  0.00700  0.00947
T-RATIO               5.09     9.98    23.91

prognost                    0.00790  0.00925
T-RATIO                        9.16    21.19

clotting                              0.0685
T-RATIO                                12.60

S           0.190    0.156   0.0965   0.0473
R-SQ        52.74    68.65    88.29    97.24
 MORE? (YES, NO, SUBCOMMAND, OR HELP)
SUBC>y

 NO VARIABLES ENTERED OR REMOVED

 MORE? (YES, NO, SUBCOMMAND, OR HELP)
SUBC>n
MTB > stepwise 'logstime' on 'clotting' 'prognost' 'enzyme' 'liver';
SUBC>fenter=10000;
SUBC>fremove=1;
SUBC>enter 'clotting' 'prognost' 'enzyme' 'liver'.

**note backward elimination NWK p.458; MTBver7 p.7-16

 STEPWISE REGRESSION OF logstime ON  4 PREDICTORS, WITH N =   54

    STEP        1        2
CONSTANT   0.4887   0.4836

clotting   0.0685   0.0692
T-RATIO     12.60    16.97

prognost  0.00925  0.00929
T-RATIO     21.19    24.30

enzyme    0.00947  0.00952
T-RATIO     23.91    31.08

liver      0.0019
T-RATIO      0.20

S          0.0473   0.0469
R-SQ        97.24    97.23
 MORE? (YES, NO, SUBCOMMAND, OR HELP)
SUBC>y

 NO VARIABLES ENTERED OR REMOVED

 MORE? (YES, NO, SUBCOMMAND, OR HELP)
SUBC>n


