pixiedust

After tidying up your analyses with the broom package, go ahead and grab the pixiedust. Customize your table output and write it to markdown, HTML, LaTeX, or even just the console. pixiedust makes it easy to customize the appearance of your tables in all of these formats by adding any number of "sprinkles", much in the same way you can add layers to a ggplot.

> fit <- lm(mpg ~ qsec + factor(am) + wt + factor(gear), data = mtcars)
> library(pixiedust)
> dust(fit) + 
+   sprinkle(col = 2:4, round = 3) + 
+   sprinkle(col = 5, fn = quote(pvalString(value))) + 
+   sprinkle_colnames(term = "Term", 
+                     estimate = "Estimate", 
+                      std.error = "SE",
+                      statistic = "T-statistic", 
+                      p.value = "P-value")

           Term Estimate    SE T-statistic P-value
1   (Intercept)    9.365 8.373       1.118    0.27
2          qsec    1.245 0.383       3.252   0.003
3   factor(am)1    3.151 1.941       1.624    0.12
4            wt   -3.926 0.743      -5.286 < 0.001
5 factor(gear)4   -0.268 1.655      -0.162    0.87
6 factor(gear)5    -0.27 2.063      -0.131     0.9

Customizing with Sprinkles

Tables can be customized by row, column, or even by a single cell by adding sprinkles to the dust object. The table below shows the currently planned and implemented sprinkles. In the "implemented" column, an 'x' indicates a customization that has been implemented, while a blank cell suggests that the customization is planned but has not yet been implemented. In the remaining columns, an 'x' indicates that the sprinkle is already implemented for the output format; an 'o' indicates that implementation is planned but not yet completed; and a blank cell indicates that the sprinkle will not be implemented (usually because the output format doesn't support the option).

dustbunny	implemented	console	markdown	html	latex
bg (background)	x			x	o
bg_pattern	x			x	o
bg_pattern_by	x			x	o
bold	x	x	x	x	o
border_collapse	x			x
border	x			x	o
border_thickness	x			x
border_units	x			x
border_style	x			x
border_color	x			x
colnames	x	x	x	x	o
fn	x	x	x	x	o
font_color	x			x	o
font_size	x			x	o
font_size_units	x			x	o
halign	x			x	o
height	x			x	o
height_units	x			x	o
italic	x	x	x	x	o
pad				o
round	x	x	x	x	o
rotate_degree				o	o
valign	x			x	o
width	x			x	o
width_units	x			x	o

A Brief Example

To demonstrate, let's look at a simple linear model. We build the model and generate the standard summary.

> fit <- lm(mpg ~ qsec + factor(am) + wt + factor(gear), data = mtcars)
> 
> summary(fit)

Call:
lm(formula = mpg ~ qsec + factor(am) + wt + factor(gear), data = mtcars)

Residuals:
    Min      1Q  Median      3Q     Max 
-3.5064 -1.5220 -0.7517  1.3841  4.6345 

Coefficients:
              Estimate Std. Error t value Pr(>|t|)    
(Intercept)     9.3650     8.3730   1.118  0.27359    
qsec            1.2449     0.3828   3.252  0.00317 ** 
factor(am)1     3.1505     1.9405   1.624  0.11654    
wt             -3.9263     0.7428  -5.286 1.58e-05 ***
factor(gear)4  -0.2682     1.6555  -0.162  0.87257    
factor(gear)5  -0.2697     2.0632  -0.131  0.89698    
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 2.55 on 26 degrees of freedom
Multiple R-squared:  0.8498,	Adjusted R-squared:  0.8209 
F-statistic: 29.43 on 5 and 26 DF,  p-value: 6.379e-10

While the summary is informative and useful, it is full of "stats-speak" and isn't necessarily in a format that is suitable for publication or submission to a client. The broom package provides the summary in tidy format that, serendipitously, it a lot closer to what we would want for formal reports.

> library(broom)
> tidy(fit)

           term   estimate std.error  statistic      p.value
1   (Intercept)  9.3650443 8.3730161  1.1184792 2.735903e-01
2          qsec  1.2449212 0.3828479  3.2517387 3.168128e-03
3   factor(am)1  3.1505178 1.9405171  1.6235455 1.165367e-01
4            wt -3.9263022 0.7427562 -5.2861251 1.581735e-05
5 factor(gear)4 -0.2681630 1.6554617 -0.1619868 8.725685e-01
6 factor(gear)5 -0.2697468 2.0631829 -0.1307430 8.969850e-01

It has been observed by some, however, that even this summary isn't quite ready for publication. There are too many decimal places, the p-value employ scientific notation, and column titles like "statistic" don't specify what type of statistic. These kinds of details aren't the purview of broom, however, as broom is focused on tidying the results of a model for further analysis (particularly with respect to comparing slightly varying models).

The pixiedust package diverts from broom's mission here and provides the ability to customize the broom output for presentation. The initial dust object returns a table that is largely similar to the broom output. Truthfully, it may be less desirable because it has converted all of those numerical values into character strings. This has the consequence of losing the numerical formatting employed by printing a data frame.

> library(pixiedust)
> dust(fit)

           term           estimate         std.error          statistic              p.value
1   (Intercept)   9.36504430865836  8.37301612033658   1.11847919245161    0.273590282784449
2          qsec   1.24492121340088 0.382847869162145    3.2517386504602  0.00316812765022556
3   factor(am)1   3.15051775932893  1.94051711270669   1.62354546563854    0.116536745986852
4            wt   -3.9263021501002 0.742756198609962   -5.2861250534807 1.58173505907644e-05
5 factor(gear)4 -0.268163000929796  1.65546166120695 -0.161986838604456    0.872568516561885
6 factor(gear)5 -0.269746805223248   2.0631829212229 -0.130743039043461    0.896984955536724

Where pixiedust shows its strength is the ease of which these tables can be customized. The code below rounds the columns estimate, std.error, and statistic to three decimal places each, and then formats the p.value into a format that happens to be one that I like.

> x <- dust(fit) + 
+   sprinkle(col = 2:4, round = 3) + 
+   sprinkle(col = 5, fn = quote(pvalString(value)))
> 
> x

           term estimate std.error statistic p.value
1   (Intercept)    9.365     8.373     1.118    0.27
2          qsec    1.245     0.383     3.252   0.003
3   factor(am)1    3.151     1.941     1.624    0.12
4            wt   -3.926     0.743    -5.286 < 0.001
5 factor(gear)4   -0.268     1.655    -0.162    0.87
6 factor(gear)5    -0.27     2.063    -0.131     0.9

Now we're almost there! Let's change up the column names, and while we're add it, let's add some "bold" markers to the statistically significant terms in order to make them stand out some (I say "bold" because the console output doesn't show up in bold, but with the markdown tags for bold text. In a rendered table, the text would actually be rendered in bold).

> x <- x + 
+   sprinkle(col = c("estimate", "p.value"), 
+            row = c(2, 4), 
+            bold = TRUE) + 
+   dust_colnames(term = "Term", 
+                 estimate = "Estimate", 
+                 std.error = "SE",
+                 statistic = "T-statistic", 
+                 p.value = "P-value")
> 
> x

           Term   Estimate    SE T-statistic     P-value
1   (Intercept)    9.365   8.373       1.118      0.27  
2          qsec  **1.245** 0.383       3.252   **0.003**
3   factor(am)1    3.151   1.941       1.624      0.12  
4            wt **-3.926** 0.743      -5.286 **< 0.001**
5 factor(gear)4   -0.268   1.655      -0.162      0.87  
6 factor(gear)5    -0.27   2.063      -0.131       0.9  

Upcoming Developments

We're just getting started! While there are a number of customizations already available or planned, here are some other ideas that I hope to implement in the future.

1. Support for multi-row table headings
2. Support for longtables in LaTeX (and a similar rendering in markdown and HTML).
3. An option to use broom's glance output in the table foot.
4. Multicolumn and multirow support
5. Perhaps an htmlTables engine
6. Option to add variable labels to broom output (if labels were given using the Hmisc::label functions
7. Option to add factor levels as a separate column to broom output

Are there other features you want or need? Please submit an issue, or contribute functionality yourself.

Development Schedule

Version	Release Description	Target Date	Acutal Date
0.1.0	Console, markdown and HTML output for simple table	1 Aug 2015	3 Aug 2015
0.2.0	Multirow table headers; footers; multipage tables	20 Aug 2015
0.3.0	Multicolumn and multirow cells in HTML	15 Sep 2015
0.4.0	Glance statistics in table footer	1 Oct 2015
0.5.0	LaTeX output for simple table	15 Oct 2015
0.6.0	Borders and backgrounds for LaTeX tables	1 Nov 2015
0.7.0	Multicolumn and multirow support for LaTeX tables	1 Dec 2015
0.8.0	Longtable support for LaTeX tables	Jan 2016
0.9.0	Adjustable cell heights and widths in LaTeX tables	Feb 2016
0.10.0	Rotated text for LaTeX tables	Mar 2016
0.11.0	Add variable labels and levels to broom output	Apr 2016
0.12.0	Add themes (cobwebs?) for batch customizations	Apr 2016
1.0.0	Release of basic, stable package	Jun 2016

bold version numbers indicate a planned release to CRAN.