Quick Start - Data Frames

library(ggplot2)
library(emphatic)

Goal

Use {emphatic} to highlight the mtcars dataset where:

6 and 8 cylinder cars only
colour each row to indicate the miles-per-gallon rating
do not colour the gear or carb columns
highlight the car with the maximum miles per gallon in hotpink
de-emphasise the numeric values to focus on the colour highlighting

Step 1: `mtcars`

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

Step 2: Use `{emphatic}`

mtcars |>
  hl('skyblue')

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

Step 3: Highlight only rows where cylinder is 6 or 8

mtcars |>
  hl('skyblue', rows = cyl %in% c(6, 8))

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

Step 4: Shade by `mpg` rating using `ggplot2::scale_colour_viridis_c()`

mtcars |>
  hl(ggplot2::scale_colour_viridis_c(), rows = cyl %in% c(6, 8), cols = mpg)

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

Step 5: Extend shading across all rows except `gear` and `carb`

mtcars |>
  hl(ggplot2::scale_colour_viridis_c(), rows = cyl %in% c(6, 8), cols = mpg, scale_apply = mpg:am)

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

Step 6: Highlight the maximum mpg

mtcars |>
  hl(ggplot2::scale_colour_viridis_c(), rows = cyl %in% c(6, 8), 
     cols = mpg, scale_apply = mpg:am) |>
  hl('hotpink', rows = mpg == max(mpg))

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

Step 7: De-emphasise the text

mtcars |>
  hl(ggplot2::scale_colour_viridis_c(), rows = cyl %in% c(6, 8), 
     cols = mpg, scale_apply = mpg:am) |>
  hl('hotpink', rows = mpg == max(mpg)) |>
  hl_adjust(text_contrast = 0.25)

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

Quick Start - Data Frames

Goal

Step 1: mtcars

Step 2: Use {emphatic}

Step 3: Highlight only rows where cylinder is 6 or 8

Step 4: Shade by mpg rating using ggplot2::scale_colour_viridis_c()

Step 5: Extend shading across all rows except gear and carb

Step 6: Highlight the maximum mpg

Step 7: De-emphasise the text

Step 1: `mtcars`

Step 2: Use `{emphatic}`

Step 4: Shade by `mpg` rating using `ggplot2::scale_colour_viridis_c()`

Step 5: Extend shading across all rows except `gear` and `carb`