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This function adds an integer column of 1's to data.

Usage

add_intercept_column(data, name = "(Intercept)")

Arguments

data

A data frame or matrix.

name

The name for the intercept column. Defaults to "(Intercept)", which is the same name that stats::lm() uses.

Value

data with an intercept column.

Details

If a column named name already exists in data, then data is returned unchanged and a warning is issued.

Examples

add_intercept_column(mtcars)
#>                     (Intercept)  mpg cyl  disp  hp drat    wt  qsec vs am
#> Mazda RX4                     1 21.0   6 160.0 110 3.90 2.620 16.46  0  1
#> Mazda RX4 Wag                 1 21.0   6 160.0 110 3.90 2.875 17.02  0  1
#> Datsun 710                    1 22.8   4 108.0  93 3.85 2.320 18.61  1  1
#> Hornet 4 Drive                1 21.4   6 258.0 110 3.08 3.215 19.44  1  0
#> Hornet Sportabout             1 18.7   8 360.0 175 3.15 3.440 17.02  0  0
#> Valiant                       1 18.1   6 225.0 105 2.76 3.460 20.22  1  0
#> Duster 360                    1 14.3   8 360.0 245 3.21 3.570 15.84  0  0
#> Merc 240D                     1 24.4   4 146.7  62 3.69 3.190 20.00  1  0
#> Merc 230                      1 22.8   4 140.8  95 3.92 3.150 22.90  1  0
#> Merc 280                      1 19.2   6 167.6 123 3.92 3.440 18.30  1  0
#> Merc 280C                     1 17.8   6 167.6 123 3.92 3.440 18.90  1  0
#> Merc 450SE                    1 16.4   8 275.8 180 3.07 4.070 17.40  0  0
#> Merc 450SL                    1 17.3   8 275.8 180 3.07 3.730 17.60  0  0
#> Merc 450SLC                   1 15.2   8 275.8 180 3.07 3.780 18.00  0  0
#> Cadillac Fleetwood            1 10.4   8 472.0 205 2.93 5.250 17.98  0  0
#> Lincoln Continental           1 10.4   8 460.0 215 3.00 5.424 17.82  0  0
#> Chrysler Imperial             1 14.7   8 440.0 230 3.23 5.345 17.42  0  0
#> Fiat 128                      1 32.4   4  78.7  66 4.08 2.200 19.47  1  1
#> Honda Civic                   1 30.4   4  75.7  52 4.93 1.615 18.52  1  1
#> Toyota Corolla                1 33.9   4  71.1  65 4.22 1.835 19.90  1  1
#> Toyota Corona                 1 21.5   4 120.1  97 3.70 2.465 20.01  1  0
#> Dodge Challenger              1 15.5   8 318.0 150 2.76 3.520 16.87  0  0
#> AMC Javelin                   1 15.2   8 304.0 150 3.15 3.435 17.30  0  0
#> Camaro Z28                    1 13.3   8 350.0 245 3.73 3.840 15.41  0  0
#> Pontiac Firebird              1 19.2   8 400.0 175 3.08 3.845 17.05  0  0
#> Fiat X1-9                     1 27.3   4  79.0  66 4.08 1.935 18.90  1  1
#> Porsche 914-2                 1 26.0   4 120.3  91 4.43 2.140 16.70  0  1
#> Lotus Europa                  1 30.4   4  95.1 113 3.77 1.513 16.90  1  1
#> Ford Pantera L                1 15.8   8 351.0 264 4.22 3.170 14.50  0  1
#> Ferrari Dino                  1 19.7   6 145.0 175 3.62 2.770 15.50  0  1
#> Maserati Bora                 1 15.0   8 301.0 335 3.54 3.570 14.60  0  1
#> Volvo 142E                    1 21.4   4 121.0 109 4.11 2.780 18.60  1  1
#>                     gear carb
#> Mazda RX4              4    4
#> Mazda RX4 Wag          4    4
#> Datsun 710             4    1
#> Hornet 4 Drive         3    1
#> Hornet Sportabout      3    2
#> Valiant                3    1
#> Duster 360             3    4
#> Merc 240D              4    2
#> Merc 230               4    2
#> Merc 280               4    4
#> Merc 280C              4    4
#> Merc 450SE             3    3
#> Merc 450SL             3    3
#> Merc 450SLC            3    3
#> Cadillac Fleetwood     3    4
#> Lincoln Continental    3    4
#> Chrysler Imperial      3    4
#> Fiat 128               4    1
#> Honda Civic            4    2
#> Toyota Corolla         4    1
#> Toyota Corona          3    1
#> Dodge Challenger       3    2
#> AMC Javelin            3    2
#> Camaro Z28             3    4
#> Pontiac Firebird       3    2
#> Fiat X1-9              4    1
#> Porsche 914-2          5    2
#> Lotus Europa           5    2
#> Ford Pantera L         5    4
#> Ferrari Dino           5    6
#> Maserati Bora          5    8
#> Volvo 142E             4    2

add_intercept_column(mtcars, "intercept")
#>                     intercept  mpg cyl  disp  hp drat    wt  qsec vs am
#> Mazda RX4                   1 21.0   6 160.0 110 3.90 2.620 16.46  0  1
#> Mazda RX4 Wag               1 21.0   6 160.0 110 3.90 2.875 17.02  0  1
#> Datsun 710                  1 22.8   4 108.0  93 3.85 2.320 18.61  1  1
#> Hornet 4 Drive              1 21.4   6 258.0 110 3.08 3.215 19.44  1  0
#> Hornet Sportabout           1 18.7   8 360.0 175 3.15 3.440 17.02  0  0
#> Valiant                     1 18.1   6 225.0 105 2.76 3.460 20.22  1  0
#> Duster 360                  1 14.3   8 360.0 245 3.21 3.570 15.84  0  0
#> Merc 240D                   1 24.4   4 146.7  62 3.69 3.190 20.00  1  0
#> Merc 230                    1 22.8   4 140.8  95 3.92 3.150 22.90  1  0
#> Merc 280                    1 19.2   6 167.6 123 3.92 3.440 18.30  1  0
#> Merc 280C                   1 17.8   6 167.6 123 3.92 3.440 18.90  1  0
#> Merc 450SE                  1 16.4   8 275.8 180 3.07 4.070 17.40  0  0
#> Merc 450SL                  1 17.3   8 275.8 180 3.07 3.730 17.60  0  0
#> Merc 450SLC                 1 15.2   8 275.8 180 3.07 3.780 18.00  0  0
#> Cadillac Fleetwood          1 10.4   8 472.0 205 2.93 5.250 17.98  0  0
#> Lincoln Continental         1 10.4   8 460.0 215 3.00 5.424 17.82  0  0
#> Chrysler Imperial           1 14.7   8 440.0 230 3.23 5.345 17.42  0  0
#> Fiat 128                    1 32.4   4  78.7  66 4.08 2.200 19.47  1  1
#> Honda Civic                 1 30.4   4  75.7  52 4.93 1.615 18.52  1  1
#> Toyota Corolla              1 33.9   4  71.1  65 4.22 1.835 19.90  1  1
#> Toyota Corona               1 21.5   4 120.1  97 3.70 2.465 20.01  1  0
#> Dodge Challenger            1 15.5   8 318.0 150 2.76 3.520 16.87  0  0
#> AMC Javelin                 1 15.2   8 304.0 150 3.15 3.435 17.30  0  0
#> Camaro Z28                  1 13.3   8 350.0 245 3.73 3.840 15.41  0  0
#> Pontiac Firebird            1 19.2   8 400.0 175 3.08 3.845 17.05  0  0
#> Fiat X1-9                   1 27.3   4  79.0  66 4.08 1.935 18.90  1  1
#> Porsche 914-2               1 26.0   4 120.3  91 4.43 2.140 16.70  0  1
#> Lotus Europa                1 30.4   4  95.1 113 3.77 1.513 16.90  1  1
#> Ford Pantera L              1 15.8   8 351.0 264 4.22 3.170 14.50  0  1
#> Ferrari Dino                1 19.7   6 145.0 175 3.62 2.770 15.50  0  1
#> Maserati Bora               1 15.0   8 301.0 335 3.54 3.570 14.60  0  1
#> Volvo 142E                  1 21.4   4 121.0 109 4.11 2.780 18.60  1  1
#>                     gear carb
#> Mazda RX4              4    4
#> Mazda RX4 Wag          4    4
#> Datsun 710             4    1
#> Hornet 4 Drive         3    1
#> Hornet Sportabout      3    2
#> Valiant                3    1
#> Duster 360             3    4
#> Merc 240D              4    2
#> Merc 230               4    2
#> Merc 280               4    4
#> Merc 280C              4    4
#> Merc 450SE             3    3
#> Merc 450SL             3    3
#> Merc 450SLC            3    3
#> Cadillac Fleetwood     3    4
#> Lincoln Continental    3    4
#> Chrysler Imperial      3    4
#> Fiat 128               4    1
#> Honda Civic            4    2
#> Toyota Corolla         4    1
#> Toyota Corona          3    1
#> Dodge Challenger       3    2
#> AMC Javelin            3    2
#> Camaro Z28             3    4
#> Pontiac Firebird       3    2
#> Fiat X1-9              4    1
#> Porsche 914-2          5    2
#> Lotus Europa           5    2
#> Ford Pantera L         5    4
#> Ferrari Dino           5    6
#> Maserati Bora          5    8
#> Volvo 142E             4    2

add_intercept_column(as.matrix(mtcars))
#>                     (Intercept)  mpg cyl  disp  hp drat    wt  qsec vs am
#> Mazda RX4                     1 21.0   6 160.0 110 3.90 2.620 16.46  0  1
#> Mazda RX4 Wag                 1 21.0   6 160.0 110 3.90 2.875 17.02  0  1
#> Datsun 710                    1 22.8   4 108.0  93 3.85 2.320 18.61  1  1
#> Hornet 4 Drive                1 21.4   6 258.0 110 3.08 3.215 19.44  1  0
#> Hornet Sportabout             1 18.7   8 360.0 175 3.15 3.440 17.02  0  0
#> Valiant                       1 18.1   6 225.0 105 2.76 3.460 20.22  1  0
#> Duster 360                    1 14.3   8 360.0 245 3.21 3.570 15.84  0  0
#> Merc 240D                     1 24.4   4 146.7  62 3.69 3.190 20.00  1  0
#> Merc 230                      1 22.8   4 140.8  95 3.92 3.150 22.90  1  0
#> Merc 280                      1 19.2   6 167.6 123 3.92 3.440 18.30  1  0
#> Merc 280C                     1 17.8   6 167.6 123 3.92 3.440 18.90  1  0
#> Merc 450SE                    1 16.4   8 275.8 180 3.07 4.070 17.40  0  0
#> Merc 450SL                    1 17.3   8 275.8 180 3.07 3.730 17.60  0  0
#> Merc 450SLC                   1 15.2   8 275.8 180 3.07 3.780 18.00  0  0
#> Cadillac Fleetwood            1 10.4   8 472.0 205 2.93 5.250 17.98  0  0
#> Lincoln Continental           1 10.4   8 460.0 215 3.00 5.424 17.82  0  0
#> Chrysler Imperial             1 14.7   8 440.0 230 3.23 5.345 17.42  0  0
#> Fiat 128                      1 32.4   4  78.7  66 4.08 2.200 19.47  1  1
#> Honda Civic                   1 30.4   4  75.7  52 4.93 1.615 18.52  1  1
#> Toyota Corolla                1 33.9   4  71.1  65 4.22 1.835 19.90  1  1
#> Toyota Corona                 1 21.5   4 120.1  97 3.70 2.465 20.01  1  0
#> Dodge Challenger              1 15.5   8 318.0 150 2.76 3.520 16.87  0  0
#> AMC Javelin                   1 15.2   8 304.0 150 3.15 3.435 17.30  0  0
#> Camaro Z28                    1 13.3   8 350.0 245 3.73 3.840 15.41  0  0
#> Pontiac Firebird              1 19.2   8 400.0 175 3.08 3.845 17.05  0  0
#> Fiat X1-9                     1 27.3   4  79.0  66 4.08 1.935 18.90  1  1
#> Porsche 914-2                 1 26.0   4 120.3  91 4.43 2.140 16.70  0  1
#> Lotus Europa                  1 30.4   4  95.1 113 3.77 1.513 16.90  1  1
#> Ford Pantera L                1 15.8   8 351.0 264 4.22 3.170 14.50  0  1
#> Ferrari Dino                  1 19.7   6 145.0 175 3.62 2.770 15.50  0  1
#> Maserati Bora                 1 15.0   8 301.0 335 3.54 3.570 14.60  0  1
#> Volvo 142E                    1 21.4   4 121.0 109 4.11 2.780 18.60  1  1
#>                     gear carb
#> Mazda RX4              4    4
#> Mazda RX4 Wag          4    4
#> Datsun 710             4    1
#> Hornet 4 Drive         3    1
#> Hornet Sportabout      3    2
#> Valiant                3    1
#> Duster 360             3    4
#> Merc 240D              4    2
#> Merc 230               4    2
#> Merc 280               4    4
#> Merc 280C              4    4
#> Merc 450SE             3    3
#> Merc 450SL             3    3
#> Merc 450SLC            3    3
#> Cadillac Fleetwood     3    4
#> Lincoln Continental    3    4
#> Chrysler Imperial      3    4
#> Fiat 128               4    1
#> Honda Civic            4    2
#> Toyota Corolla         4    1
#> Toyota Corona          3    1
#> Dodge Challenger       3    2
#> AMC Javelin            3    2
#> Camaro Z28             3    4
#> Pontiac Firebird       3    2
#> Fiat X1-9              4    1
#> Porsche 914-2          5    2
#> Lotus Europa           5    2
#> Ford Pantera L         5    4
#> Ferrari Dino           5    6
#> Maserati Bora          5    8
#> Volvo 142E             4    2