Format content

By default, the displayed content of each cell will be the result of a simple formatting. The content can also be composed as the result of a concatenation of several chunks.

There are formatter functions to define how columns content will be display (e.g. to define the number of decimal). This is a column-wise operation.

User can also have more control over displayed content by using function compose. The function enable to define the elements composing the paragraph and their respective formats. It can also be used to mix text chunks and images.

Simple functions for formatting content

Theses are high level functions that should satisfy most of the usual needs. They can be used to define the formatting of one or more columns and eventually on a subset of rows.

Each accept a prefix and suffix argument that can be used to add a currency symbol for example. Also they all have na_str argument (defaut to ""), the string to use when data are not available.

dat <- head(mtcars, n = 10)
dat[3:7, 1] <- NA
dat[, 2] <- dat[, 6] * 1000000

ft <- flextable(dat)
ft

mpg

cyl

disp

hp

drat

wt

qsec

vs

am

gear

carb

21.0

2620000

160.0

110

3.90

2.620

16.46

0

1

4

4

21.0

2875000

160.0

110

3.90

2.875

17.02

0

1

4

4

NA

2320000

108.0

93

3.85

2.320

18.61

1

1

4

1

NA

3215000

258.0

110

3.08

3.215

19.44

1

0

3

1

NA

3440000

360.0

175

3.15

3.440

17.02

0

0

3

2

NA

3460000

225.0

105

2.76

3.460

20.22

1

0

3

1

NA

3570000

360.0

245

3.21

3.570

15.84

0

0

3

4

24.4

3190000

146.7

62

3.69

3.190

20.00

1

0

4

2

22.8

3150000

140.8

95

3.92

3.150

22.90

1

0

4

2

19.2

3440000

167.6

123

3.92

3.440

18.30

1

0

4

4

num_keys <- c("mpg", "disp", "drat", "wt", "qsec")
int_keys <- c("cyl", "hp", "vs", "am", "gear", "carb")

ft <- colformat_num(x = ft, col_keys = num_keys, big.mark = ",", digits = 2, na_str = "missing")
#> Warning in colformat_num.flextable(x = ft, col_keys = num_keys, big.mark =
#> ",", : argument col_keys is deprecated in favor of argument j
ft <- colformat_int(x = ft, col_keys = int_keys, big.mark = ",")
#> Warning in colformat_int.flextable(x = ft, col_keys = int_keys, big.mark =
#> ","): argument col_keys is deprecated in favor of argument j
autofit(ft)

mpg

cyl

disp

hp

drat

wt

qsec

vs

am

gear

carb

21.00

2,620,000

160.00

110

3.90

2.62

16.46

0

1

4

4

21.00

2,875,000

160.00

110

3.90

2.88

17.02

0

1

4

4

missing

2,320,000

108.00

93

3.85

2.32

18.61

1

1

4

1

missing

3,215,000

258.00

110

3.08

3.21

19.44

1

0

3

1

missing

3,440,000

360.00

175

3.15

3.44

17.02

0

0

3

2

missing

3,460,000

225.00

105

2.76

3.46

20.22

1

0

3

1

missing

3,570,000

360.00

245

3.21

3.57

15.84

0

0

3

4

24.40

3,190,000

146.70

62

3.69

3.19

20.00

1

0

4

2

22.80

3,150,000

140.80

95

3.92

3.15

22.90

1

0

4

2

19.20

3,440,000

167.60

123

3.92

3.44

18.30

1

0

4

4

Their names is col_format_* as the first version was not working with rows subset. This limitation is no more true and the functions should then be named format_int, format_num… as they can operate on rows and columns.

set_formatter function

It is possible to define the functions that will be used to format the data.frame values into strings. set_formatter set column formatter functions.

ft <- flextable(head(mtcars, n = 10 ), 
                   col_keys = c("gear", "mpg", "qsec"))
ft <- set_formatter(ft, 
    mpg = function(x) sprintf("%.04f", x),
    gear = function(x) sprintf("%.0f gears", x)
  )
ft <- theme_booktabs(ft)
ft <- autofit(ft)
ft

gear

mpg

qsec

4 gears

21.0000

16.46

4 gears

21.0000

17.02

4 gears

22.8000

18.61

3 gears

21.4000

19.44

3 gears

18.7000

17.02

3 gears

18.1000

20.22

3 gears

14.3000

15.84

4 gears

24.4000

20.00

4 gears

22.8000

22.90

4 gears

19.2000

18.30

compose function

Usage

flextable content can be defined with function compose.

It lets user control the formated content at the cell level of the table. It is possible to define a content for a row subset and a column as well as on the whole column. One can mix images and text (but not with PowerPoint because PowerPoint can not do it).

Below the starting point of next illustrations:

am

gear

mpg

drat

qsec

1

4

21.0

3.90

16.46

1

4

21.0

3.90

17.02

1

4

22.8

3.85

18.61

0

3

21.4

3.08

19.44

0

3

18.7

3.15

17.02

0

3

18.1

2.76

20.22

The function requires a call to as_paragraph which will concatenate text or images chunks as a paragraph.

The following example shows how to control the format of displayed values and how to associate them with specific text formatting properties (bold red text):

am

gear

mpg

drat

qsec

1

4

mpg value is 21.0

3.90

16.46

1

4

mpg value is 21.0

3.90

17.02

1

4

mpg value is 22.8

3.85

18.61

0

3

mpg value is 21.4

3.08

19.44

0

3

mpg value is 18.7

3.15

17.02

0

3

mpg value is 18.1

2.76

20.22

With that system, it’s easy to concatenate multiple values:

am

gear

mpg

drat

qsec

1

4

mpg value is 21.0 with # 4

3.90

16.46

1

4

mpg value is 21.0 with # 4

3.90

17.02

1

4

mpg value is 22.8 with # 1

3.85

18.61

0

3

mpg value is 21.4 with # 1

3.08

19.44

0

3

mpg value is 18.7 with # 2

3.15

17.02

0

3

mpg value is 18.1 with # 1

2.76

20.22

Or to define specific title headers:

am

gear

Miles/(US) gallon * with num of carb.

drat

qsec

1

4

mpg value is 21.0 with # 4

3.90

16.46

1

4

mpg value is 21.0 with # 4

3.90

17.02

1

4

mpg value is 22.8 with # 1

3.85

18.61

0

3

mpg value is 21.4 with # 1

3.08

19.44

0

3

mpg value is 18.7 with # 2

3.15

17.02

0

3

mpg value is 18.1 with # 1

2.76

20.22

Limitation for PowerPoint

Using images in flextable is not supported when output format is PowerPoint. This is not a choice nor a unimplemented feature. This is because PowerPoint is not able to embed images in a table cell. That’s a PowerPoint limitation.

If beeing able to display images in PowerPoint table is important to you, you can use the plot function or the save_as_image and embed the result in the PowerPoint. You will of course loose ability to edit the table in PowerPoint.

Images

Function compose supports images insertion. Use function as_image in as_paragraph call:

am

gear

Miles/(US) gallon * with num of carb.

drat

qsec

1

4

mpg value is 21.0 with # 4

3.90

16.46

1

4

mpg value is 21.0 with # 4

3.90

17.02

1

4

mpg value is 22.8 with # 1

3.85

0

3

mpg value is 21.4 with # 1

3.08

0

3

mpg value is 18.7 with # 2

3.15

17.02

0

3

mpg value is 18.1 with # 1

2.76

minibar

Function compose supports mini barplots insertion. Use function minibar in as_paragraph call:

Sepal.Length

Sepal.Width

Petal.Length

Petal.Width

Species

3.5

1.4

0.2

setosa

3.0

1.4

0.2

setosa

3.2

1.3

0.2

setosa

3.1

1.5

0.2

setosa

3.6

1.4

0.2

setosa

3.9

1.7

0.4

setosa

3.4

1.4

0.3

setosa

3.4

1.5

0.2

setosa

2.9

1.4

0.2

setosa

3.1

1.5

0.1

setosa

linerange

Function compose supports mini linerange insertion. Use function linerange in as_paragraph call:

Sepal.Length

Sepal.Width

Petal.Length

Petal.Width

Species

3.5

1.4

0.2

setosa

3.0

1.4

0.2

setosa

3.2

1.3

0.2

setosa

3.1

1.5

0.2

setosa

3.6

1.4

0.2

setosa

3.9

1.7

0.4

setosa

3.4

1.4

0.3

setosa

3.4

1.5

0.2

setosa

2.9

1.4

0.2

setosa

3.1

1.5

0.1

setosa

Sugar functions for complex formatting

Functions as_b, as_i, as_sub, as_sup are special functions that can be used together. They set a value as bold, italic, subscripted or superscripted. This is particularly useful when the headers need complex formatting.

Species

col1

setosa

5.006

versicolor

5.936

virginica

6.588

Species

µblah

setosa

5.006

versicolor

5.936

virginica

6.588

footnotes

Adding footnotes is possible by using function compose but it requires a two step approach (add the reference symbol and add the corresponding footnote in the footer part).

To make the process simpler, use function footnote that will ease the addition of footnotes.

ft <- flextable(head(iris))
ft <- footnote( ft, i = 1, j = 1:3,
            value = as_paragraph(
              c("This is footnote one",
                "This is footnote two",
                "This is footnote three")
            ),
            ref_symbols = c("a", "b", "c"),
            part = "header")
ft <- valign(ft, valign = "bottom", part = "header")
autofit(ft)

Sepal.Lengtha

Sepal.Widthb

Petal.Lengthc

Petal.Width

Species

5.1

3.5

1.4

0.2

setosa

4.9

3.0

1.4

0.2

setosa

4.7

3.2

1.3

0.2

setosa

4.6

3.1

1.5

0.2

setosa

5.0

3.6

1.4

0.2

setosa

5.4

3.9

1.7

0.4

setosa

aThis is footnote one

bThis is footnote two

cThis is footnote three