Automatically Format Export Tables

Suggest an appropriate alignment, number of digits, and display type for xtable.

autoformat(xtab, zap = getOption("digits"))

xalign(x, pad = TRUE)
xdigits(x, pad = TRUE, zap = getOption("digits"))
xdisplay(x, pad = TRUE)

Arguments

xtab

an object of class xtable.

x

a vector, matrix, or data frame.

pad

whether to format row names, when x is two-dimensional.

zap

the number of digits passed to zapsmall.

Value

autoformat returns a copy of xtab, after applying xalign, xdigits, and xdisplay.

xalign returns a character vector consisting of "l" and "r" elements, for left/right alignment.

xdigits returns an integer vector.

xdisplay returns a character vector of "d", "f", and "s" elements, for integer/double/string display.

Author

Arni Magnusson.

See also

xtable, align, digits, display

Examples

## 1  Vector
xalign(precip)
#> [1] "r"
xdigits(precip)
#> [1] 1
xdisplay(precip)
#> [1] "f"


## 2  Data frame
head(mtcars)
#>                    mpg cyl disp  hp drat    wt  qsec vs am gear carb
#> Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
#> Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
#> Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
#> Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
#> Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
#> Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1
xdigits(mtcars, pad = FALSE)
#>  mpg  cyl disp   hp drat   wt qsec   vs   am gear carb 
#>    1    0    1    0    2    3    2    0    0    0    0 
xdigits(mtcars, pad = TRUE)
#>       mpg  cyl disp   hp drat   wt qsec   vs   am gear carb 
#>    0    1    0    1    0    2    3    2    0    0    0    0 
xalign(mtcars)
#>       mpg  cyl disp   hp drat   wt qsec   vs   am gear carb 
#>  "l"  "r"  "r"  "r"  "r"  "r"  "r"  "r"  "r"  "r"  "r"  "r" 
xdisplay(mtcars)
#>       mpg  cyl disp   hp drat   wt qsec   vs   am gear carb 
#>  "s"  "f"  "d"  "f"  "d"  "f"  "f"  "f"  "d"  "d"  "d"  "d" 


## 3  Autoformat when xtable is created
xtable(mtcars, align = xalign(mtcars), digits = xdigits(mtcars),
       display = xdisplay(mtcars))
#> % latex table generated in R 4.5.1 by xtable 1.8-4 package
#> % Fri Oct 31 17:35:09 2025
#> \begin{table}[ht]
#> \centering
#> \begin{tabular}{lrrrrrrrrrrr}
#>   \hline
#>  & mpg & cyl & disp & hp & drat & wt & qsec & vs & am & gear & carb \\ 
#>   \hline
#> 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 \\ 
#>    \hline
#> \end{tabular}
#> \end{table}

## equivalent shortcut
xtable(mtcars, auto = TRUE)
#> % latex table generated in R 4.5.1 by xtable 1.8-4 package
#> % Fri Oct 31 17:35:09 2025
#> \begin{table}[ht]
#> \centering
#> \begin{tabular}{lrrrrrrrrrrr}
#>   \hline
#>  & mpg & cyl & disp & hp & drat & wt & qsec & vs & am & gear & carb \\ 
#>   \hline
#> 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 \\ 
#>    \hline
#> \end{tabular}
#> \end{table}


## 4  Autoformat existing xtable
mt <- xtable(mtcars)
align(mt) <- xalign(mt)
digits(mt) <- xdigits(mt)
display(mt) <- xdisplay(mt)

## equivalent shortcut
mt <- autoformat(mt)