How to print (to paper) a nicely-formatted data frame

Question

I'd like to print nicely-formatted data frames to paper, ideally from within a script. (I am trying to collect data using an instrument and automatically process and print it using an R script).

Right now I can write a data frame to a text file using write.table(), but this has two problems:

1. The resulting text file is poorly formatted (columns do not necessarily line up with their headings) and
2. I don't know how to print a text file from within R.

I'm looking more for general strategies than for specific code (although code would be great too!). Would Sweave be the most convenient solution? In principle can I use socketConnection() to print to a printer - and if so, where can I learn about how to use it (I didn't find the documentation to be very helpful).

Answer 1

Here is a quick and easy possibility using grid.table from the gridExtra package:

library(gridExtra)
pdf("data_output.pdf", height=11, width=8.5)
grid.table(mtcars)
dev.off()

If your data doesn't fit on the page, you can reduce the text size grid.table(mtcars, gp=gpar(fontsize=8)). This may not be very flexible, nor easy to generalize or automate.

Answer 2

I would suggest xtable in combination with LaTeX documents. Have a look at the examples in this pdf:

You could also directly combine this with Sweave or knitr.

Answer 3

Surprised nobody has mentioned the stargazer package for nice printing of data.

You can output a nice-looking text file:

stargazer(mtcars, type = 'text', out = 'out.txt')

============================================
Statistic N   Mean   St. Dev.  Min     Max  
--------------------------------------------
mpg       32 20.091   6.027   10.400 33.900 
cyl       32  6.188   1.786     4       8   
disp      32 230.722 123.939  71.100 472.000
hp        32 146.688  68.563    52     335  
drat      32  3.597   0.535   2.760   4.930 
wt        32  3.217   0.978   1.513   5.424 
qsec      32 17.849   1.787   14.500 22.900 
vs        32  0.438   0.504     0       1   
am        32  0.406   0.499     0       1   
gear      32  3.688   0.738     3       5   
carb      32  2.812   1.615     1       8   
--------------------------------------------

Or even HTML:

stargazer(mtcars, type = 'html', out = 'out.html')

<table style="text-align:center"><tr><td colspan="6" style="border-bottom: 1px solid black"></td></tr><tr><td style="text-align:left">Statistic</td><td>N</td><td>Mean</td><td>St. Dev.</td><td>Min</td><td>Max</td></tr>
<tr><td colspan="6" style="border-bottom: 1px solid black"></td></tr><tr><td style="text-align:left">mpg</td><td>32</td><td>20.091</td><td>6.027</td><td>10.400</td><td>33.900</td></tr>
<tr><td style="text-align:left">cyl</td><td>32</td><td>6.188</td><td>1.786</td><td>4</td><td>8</td></tr>
<tr><td style="text-align:left">disp</td><td>32</td><td>230.722</td><td>123.939</td><td>71.100</td><td>472.000</td></tr>
<tr><td style="text-align:left">hp</td><td>32</td><td>146.688</td><td>68.563</td><td>52</td><td>335</td></tr>
<tr><td style="text-align:left">drat</td><td>32</td><td>3.597</td><td>0.535</td><td>2.760</td><td>4.930</td></tr>
<tr><td style="text-align:left">wt</td><td>32</td><td>3.217</td><td>0.978</td><td>1.513</td><td>5.424</td></tr>
<tr><td style="text-align:left">qsec</td><td>32</td><td>17.849</td><td>1.787</td><td>14.500</td><td>22.900</td></tr>
<tr><td style="text-align:left">vs</td><td>32</td><td>0.438</td><td>0.504</td><td>0</td><td>1</td></tr>
<tr><td style="text-align:left">am</td><td>32</td><td>0.406</td><td>0.499</td><td>0</td><td>1</td></tr>
<tr><td style="text-align:left">gear</td><td>32</td><td>3.688</td><td>0.738</td><td>3</td><td>5</td></tr>
<tr><td style="text-align:left">carb</td><td>32</td><td>2.812</td><td>1.615</td><td>1</td><td>8</td></tr>
<tr><td colspan="6" style="border-bottom: 1px solid black"></td></tr></table>