Formatting numbers

Notation and tables

Roland Krause

MADS6

Wednesday, 4 March 2026

Formating numbers

Three types of numbers

Exact numbers
Measured numbers

Numbers with an associated error

Computed numbers

Numbers resulting from (potentially complex) calculation of a measured quantity or simulation.

Note

In data science, we are frequently facing values with limited detail on their measurements. That’s not an invitation to ignore the fact.

Exact numbers

Counted objects

3 bikes
7 people
1015 items sold

Note

In text, we would write “three bikes and seven people”.

Exact relation

1km = 1000m

Speed of light

299 792 458 m/s (a definition)

Measured numbers

Data with natural errors

Multiple measurements will return differing results
Measurements by different people will return different results.
Precision is naturally limited

Why we care

In data science we typically do not measure data ourselves.

The value we print to a report however conveys a meaning of certainty.

Significant digits

Types of zeros

Leading zeros
| ||||||
0.000000230453400
          |    ||
Captive zero   Trailing zeros

Significant zeros

All non-zero numbers are significant.
Zeros surrounded by other numbers are significant.
Leading zeros are never significant
Trailing zeros after a decimal if they have been measured.

Examples

Value	Digits	Explanation
1642 m	4	All non-zero
10.303 ml	5	Captive zeros
67.0 g	3	Trailing measured zero
0.00053503	5	All leading zeros irrelevant

Your turn

How many significant digits?

1200001
12.000
0.0000000001
0.0010000001

Solution

Value	Digits	Explanation
1200001 m	7	Mostly captive zeros
12.000 g	5	If measured
0.0000000001	1	All leading zeros irrelevant
0.0010000001	8

How to display numbers

Many numbers in data science are not in our “nice” range from 0 - 1000.

Example numbers

my_val <- (c(0.1, 0.00000000123, 13/150660001, 761231, -3.243) )
my_val

[1]  1.00000e-01  1.23000e-09  8.62870e-08  7.61231e+05
[5] -3.24300e+00

Numbers printed to the console can be deceiving

print(1)

[1] 1

print(1.00001)

[1] 1.00001

print(c(1, 1.00001))

[1] 1.00000 1.00001

But you can’t say Base R is doing a bad job…

Common notation systems

Decimal notation

Scientific notation

Math vs computer science

Should be \(1.9 \times 10^{-4}\) but we usually get to see 1.9e-4.

$1.9 \times 10^{-4}$

Engineering notation

Exponents are a multiple of three.

tibble(
  dec = num(my_val, notation = "dec"),
  sci = num(my_val, notation = "sci"),
  eng = num(my_val, notation = "eng")
)

# A tibble: 5 × 3
                 dec      sci       eng
               <dec>    <sci>     <eng>
1      0.1            1   e-1 100   e-3
2      0.00000000123  1.23e-9   1.23e-9
3      0.0000000863   8.63e-8  86.3 e-9
4 761231              7.61e+5 761.  e+3
5     -3.24          -3.24e+0  -3.24e+0

Using the pillar::num()

Formating the C-style `sprintf()`

Formating

%i - Integer values
%f - Decimal numerical format (fixed)
%e - Scientific notation %E with capital E
%g - Best of both worlds: decimal if exponent is < -4.

Many other options for padding, currency symbols

Examples

sprintf("%f", my_val)

[1] "0.100000"      "0.000000"      "0.000000"     
[4] "761231.000000" "-3.243000"

sprintf("%e", my_val)

[1] "1.000000e-01"  "1.230000e-09"  "8.628700e-08" 
[4] "7.612310e+05"  "-3.243000e+00"

sprintf("%G", my_val)

[1] "0.1"        "1.23E-09"   "8.6287E-08" "761231"    
[5] "-3.243"

sprintf("%i", my_val)

Error in `sprintf()`:
! invalid format '%i'; use format %f, %e, %g or %a for numeric objects

Python

Modern Python is using sprintf-style syntax in its str.format() function. Using the sprintf functions is deprecated.

Check the documentation.

Rounding to significant digits

Display of numbers carries a meaning

Compare different numbers - Eight, 12.0, 1.76-e7, four, 3.0

Generally: Round to three significant digits

signif(my_val, 3)

[1]  1.00e-01  1.23e-09  8.63e-08  7.61e+05 -3.24e+00

Rounding measured data

Adding numbers need to be rounded to the least precise digit

[1] 11.961

[1] 12

Least precise value (4.5) carries a single digit.

Tables

Data in tables

Basic conventions

Text is left-aligned.
Numbers are aligned at the decimal place

Base R is doing this nicely but the result is not publication quality.

      species    island bill_len bill_dep
1      Adelie     Dream     32.1     15.5
2      Adelie     Dream     33.1     16.1
3      Adelie Torgersen     33.5     19.0
4      Adelie     Dream     34.0     17.1
5      Adelie Torgersen     34.1     18.1
6      Adelie Torgersen     34.4     18.4
7      Adelie    Biscoe     34.5     18.1
8      Adelie Torgersen     34.6     21.1
9      Adelie Torgersen     34.6     17.2
10     Adelie    Biscoe     35.0     17.9
11     Adelie    Biscoe     35.0     17.9
12     Adelie Torgersen     35.1     19.4
13     Adelie Torgersen     35.2     15.9
14     Adelie    Biscoe     35.3     18.9
15     Adelie    Biscoe     35.5     16.2
16     Adelie Torgersen     35.5     17.5
17     Adelie     Dream     35.6     17.5
18     Adelie    Biscoe     35.7     16.9
19     Adelie     Dream     35.7     18.0
20     Adelie Torgersen     35.7     17.0
21     Adelie    Biscoe     35.9     19.2
22     Adelie Torgersen     35.9     16.6
23     Adelie     Dream     36.0     18.5
24     Adelie     Dream     36.0     17.9
25     Adelie     Dream     36.0     17.8
26     Adelie     Dream     36.0     17.1
27     Adelie Torgersen     36.2     16.1
28     Adelie     Dream     36.2     17.3
29     Adelie Torgersen     36.2     17.2
30     Adelie     Dream     36.3     19.5
31     Adelie     Dream     36.4     17.0
32     Adelie    Biscoe     36.4     17.1
33     Adelie     Dream     36.5     18.0
34     Adelie    Biscoe     36.5     16.6
35     Adelie Torgersen     36.6     17.8
36     Adelie     Dream     36.6     18.4
37     Adelie Torgersen     36.7     19.3
38     Adelie Torgersen     36.7     18.8
39     Adelie     Dream     36.8     18.5
40     Adelie     Dream     36.9     18.6
41     Adelie     Dream     37.0     16.9
42     Adelie     Dream     37.0     16.5
43     Adelie     Dream     37.2     18.1
44     Adelie Torgersen     37.2     19.4
45     Adelie     Dream     37.3     17.8
46     Adelie Torgersen     37.3     20.5
47     Adelie     Dream     37.3     16.8
48     Adelie     Dream     37.5     18.9
49     Adelie     Dream     37.5     18.5
50     Adelie     Dream     37.6     19.3
51     Adelie    Biscoe     37.6     19.1
52     Adelie    Biscoe     37.6     17.0
53     Adelie    Biscoe     37.7     18.7
54     Adelie    Biscoe     37.7     16.0
55     Adelie Torgersen     37.7     19.8
56     Adelie Torgersen     37.8     17.1
57     Adelie Torgersen     37.8     17.3
58     Adelie    Biscoe     37.8     18.3
59     Adelie    Biscoe     37.8     20.0
60     Adelie     Dream     37.8     18.1
61     Adelie    Biscoe     37.9     18.6
62     Adelie    Biscoe     37.9     18.6
63     Adelie     Dream     38.1     18.6
64     Adelie    Biscoe     38.1     17.0
65     Adelie    Biscoe     38.1     16.5
66     Adelie     Dream     38.1     17.6
67     Adelie    Biscoe     38.2     18.1
68     Adelie    Biscoe     38.2     20.0
69     Adelie     Dream     38.3     19.2
70     Adelie Torgersen     38.5     17.9
71     Adelie Torgersen     38.6     21.2
72     Adelie    Biscoe     38.6     17.2
73     Adelie Torgersen     38.6     17.0
74     Adelie Torgersen     38.7     19.0
75     Adelie    Biscoe     38.8     17.2
76     Adelie     Dream     38.8     20.0
77     Adelie Torgersen     38.8     17.6
78     Adelie Torgersen     38.9     17.8
79     Adelie     Dream     38.9     18.8
80     Adelie    Biscoe     39.0     17.5
81     Adelie Torgersen     39.0     17.1
82     Adelie     Dream     39.0     18.7
83     Adelie Torgersen     39.1     18.7
84     Adelie Torgersen     39.2     19.6
85     Adelie     Dream     39.2     21.1
86     Adelie     Dream     39.2     18.6
87     Adelie Torgersen     39.3     20.6
88     Adelie Torgersen     39.5     17.4
89     Adelie     Dream     39.5     16.7
90     Adelie     Dream     39.5     17.8
91     Adelie     Dream     39.6     18.8
92     Adelie    Biscoe     39.6     17.7
93     Adelie Torgersen     39.6     17.2
94     Adelie     Dream     39.6     18.1
95     Adelie    Biscoe     39.6     20.7
96     Adelie Torgersen     39.7     18.4
97     Adelie    Biscoe     39.7     18.9
98     Adelie    Biscoe     39.7     17.7
99     Adelie     Dream     39.7     17.9
100    Adelie     Dream     39.8     19.1
101    Adelie    Biscoe     40.1     18.9
102    Adelie Torgersen     40.2     17.0
103    Adelie     Dream     40.2     20.1
104    Adelie     Dream     40.2     17.1
105    Adelie Torgersen     40.3     18.0
106    Adelie     Dream     40.3     18.5
107    Adelie    Biscoe     40.5     17.9
108    Adelie    Biscoe     40.5     18.9
109    Adelie    Biscoe     40.6     18.6
110    Adelie    Biscoe     40.6     18.8
111    Adelie Torgersen     40.6     19.0
112    Adelie     Dream     40.6     17.2
113    Adelie     Dream     40.7     17.0
114    Adelie     Dream     40.8     18.4
115    Adelie     Dream     40.8     18.9
116    Adelie     Dream     40.9     18.9
117    Adelie Torgersen     40.9     16.8
118    Gentoo    Biscoe     40.9     13.7
119 Chinstrap     Dream     40.9     16.6
120    Adelie    Biscoe     41.0     20.0
121    Adelie Torgersen     41.1     17.6
122    Adelie     Dream     41.1     19.0
123    Adelie    Biscoe     41.1     18.2
124    Adelie    Biscoe     41.1     19.1
125    Adelie     Dream     41.1     18.1
126    Adelie Torgersen     41.1     18.6
127    Adelie     Dream     41.1     17.5
128    Adelie    Biscoe     41.3     21.1
129    Adelie     Dream     41.3     20.3
130    Adelie    Biscoe     41.4     18.6
131    Adelie Torgersen     41.4     18.5
132    Adelie Torgersen     41.5     18.3
133    Adelie     Dream     41.5     18.5
134    Adelie    Biscoe     41.6     18.0
135    Gentoo    Biscoe     41.7     14.7
136    Adelie Torgersen     41.8     19.4
137    Adelie Torgersen     42.0     20.2
138    Adelie    Biscoe     42.0     19.5
139    Gentoo    Biscoe     42.0     13.5
140    Adelie Torgersen     42.1     19.1
141    Adelie     Dream     42.2     18.5
142    Adelie    Biscoe     42.2     19.5
143    Adelie     Dream     42.3     21.2
144 Chinstrap     Dream     42.4     17.3
145    Adelie Torgersen     42.5     20.7
146 Chinstrap     Dream     42.5     16.7
147 Chinstrap     Dream     42.5     17.3
148    Gentoo    Biscoe     42.6     13.7
149    Adelie    Biscoe     42.7     18.3
150    Gentoo    Biscoe     42.7     13.7
151    Adelie Torgersen     42.8     18.5
152    Gentoo    Biscoe     42.8     14.2
153    Adelie Torgersen     42.9     17.6
154    Gentoo    Biscoe     42.9     13.1
155    Adelie Torgersen     43.1     19.2
156    Adelie     Dream     43.2     18.5
157    Adelie    Biscoe     43.2     19.0
158    Gentoo    Biscoe     43.2     14.5
159 Chinstrap     Dream     43.2     16.6
160    Gentoo    Biscoe     43.3     13.4
161    Gentoo    Biscoe     43.3     14.0
162    Gentoo    Biscoe     43.4     14.4
163    Gentoo    Biscoe     43.5     14.2
164    Gentoo    Biscoe     43.5     15.2
165 Chinstrap     Dream     43.5     18.1
166    Gentoo    Biscoe     43.6     13.9
167    Gentoo    Biscoe     43.8     13.9
168    Gentoo    Biscoe     44.0     13.6
169    Adelie     Dream     44.1     19.7
170    Adelie Torgersen     44.1     18.0
171    Gentoo    Biscoe     44.4     17.3
172    Gentoo    Biscoe     44.5     14.3
173    Gentoo    Biscoe     44.5     14.7
174    Gentoo    Biscoe     44.5     15.7
175    Gentoo    Biscoe     44.9     13.3
176    Gentoo    Biscoe     44.9     13.8
177    Gentoo    Biscoe     45.0     15.4
178    Gentoo    Biscoe     45.1     14.5
179    Gentoo    Biscoe     45.1     14.5
180    Gentoo    Biscoe     45.1     14.4
181    Gentoo    Biscoe     45.2     15.8
182    Gentoo    Biscoe     45.2     13.8
183    Gentoo    Biscoe     45.2     16.4
184    Gentoo    Biscoe     45.2     14.8
185 Chinstrap     Dream     45.2     17.8
186 Chinstrap     Dream     45.2     16.6
187    Gentoo    Biscoe     45.3     13.7
188    Gentoo    Biscoe     45.3     13.8
189    Gentoo    Biscoe     45.4     14.6
190 Chinstrap     Dream     45.4     18.7
191    Gentoo    Biscoe     45.5     13.7
192    Gentoo    Biscoe     45.5     13.9
193    Gentoo    Biscoe     45.5     15.0
194    Gentoo    Biscoe     45.5     14.5
195 Chinstrap     Dream     45.5     17.0
196    Adelie    Biscoe     45.6     20.3
197 Chinstrap     Dream     45.6     19.4
198    Gentoo    Biscoe     45.7     13.9
199 Chinstrap     Dream     45.7     17.3
200 Chinstrap     Dream     45.7     17.0
201    Adelie Torgersen     45.8     18.9
202    Gentoo    Biscoe     45.8     14.6
203    Gentoo    Biscoe     45.8     14.2
204 Chinstrap     Dream     45.9     17.1
205    Adelie Torgersen     46.0     21.5
206 Chinstrap     Dream     46.0     18.9
207    Gentoo    Biscoe     46.1     13.2
208    Gentoo    Biscoe     46.1     15.1
209 Chinstrap     Dream     46.1     18.2
210    Gentoo    Biscoe     46.2     14.5
211    Gentoo    Biscoe     46.2     14.9
212    Gentoo    Biscoe     46.2     14.4
213    Gentoo    Biscoe     46.2     14.1
214 Chinstrap     Dream     46.2     17.5
215    Gentoo    Biscoe     46.3     15.8
216    Gentoo    Biscoe     46.4     15.6
217    Gentoo    Biscoe     46.4     15.0
218 Chinstrap     Dream     46.4     18.6
219 Chinstrap     Dream     46.4     17.8
220    Gentoo    Biscoe     46.5     13.5
221    Gentoo    Biscoe     46.5     14.5
222    Gentoo    Biscoe     46.5     14.4
223    Gentoo    Biscoe     46.5     14.8
224 Chinstrap     Dream     46.5     17.9
225    Gentoo    Biscoe     46.6     14.2
226 Chinstrap     Dream     46.6     17.8
227    Gentoo    Biscoe     46.7     15.3
228 Chinstrap     Dream     46.7     17.9
229    Gentoo    Biscoe     46.8     15.4
230    Gentoo    Biscoe     46.8     16.1
231    Gentoo    Biscoe     46.8     14.3
232 Chinstrap     Dream     46.8     16.5
233    Gentoo    Biscoe     46.9     14.6
234 Chinstrap     Dream     46.9     16.6
235 Chinstrap     Dream     47.0     17.3
236    Gentoo    Biscoe     47.2     15.5
237    Gentoo    Biscoe     47.2     13.7
238    Gentoo    Biscoe     47.3     15.3
239    Gentoo    Biscoe     47.3     13.8
240    Gentoo    Biscoe     47.4     14.6
241    Gentoo    Biscoe     47.5     14.2
242    Gentoo    Biscoe     47.5     14.0
243    Gentoo    Biscoe     47.5     15.0
244 Chinstrap     Dream     47.5     16.8
245    Gentoo    Biscoe     47.6     14.5
246 Chinstrap     Dream     47.6     18.3
247    Gentoo    Biscoe     47.7     15.0
248    Gentoo    Biscoe     47.8     15.0
249    Gentoo    Biscoe     48.1     15.1
250 Chinstrap     Dream     48.1     16.4
251    Gentoo    Biscoe     48.2     14.3
252    Gentoo    Biscoe     48.2     15.6
253    Gentoo    Biscoe     48.4     14.6
254    Gentoo    Biscoe     48.4     16.3
255    Gentoo    Biscoe     48.4     14.4
256    Gentoo    Biscoe     48.5     14.1
257    Gentoo    Biscoe     48.5     15.0
258 Chinstrap     Dream     48.5     17.5
259    Gentoo    Biscoe     48.6     16.0
260    Gentoo    Biscoe     48.7     14.1
261    Gentoo    Biscoe     48.7     15.1
262    Gentoo    Biscoe     48.7     15.7
263    Gentoo    Biscoe     48.8     16.2
264    Gentoo    Biscoe     49.0     16.1
265 Chinstrap     Dream     49.0     19.5
266 Chinstrap     Dream     49.0     19.6
267    Gentoo    Biscoe     49.1     14.8
268    Gentoo    Biscoe     49.1     14.5
269    Gentoo    Biscoe     49.1     15.0
270    Gentoo    Biscoe     49.2     15.2
271 Chinstrap     Dream     49.2     18.2
272    Gentoo    Biscoe     49.3     15.7
273 Chinstrap     Dream     49.3     19.9
274    Gentoo    Biscoe     49.4     15.8
275    Gentoo    Biscoe     49.5     16.2
276    Gentoo    Biscoe     49.5     16.1
277 Chinstrap     Dream     49.5     19.0
278    Gentoo    Biscoe     49.6     16.0
279    Gentoo    Biscoe     49.6     15.0
280 Chinstrap     Dream     49.6     18.2
281 Chinstrap     Dream     49.7     18.6
282    Gentoo    Biscoe     49.8     16.8
283    Gentoo    Biscoe     49.8     15.9
284 Chinstrap     Dream     49.8     17.3
285    Gentoo    Biscoe     49.9     16.1
286    Gentoo    Biscoe     50.0     16.3
287    Gentoo    Biscoe     50.0     15.2
288    Gentoo    Biscoe     50.0     15.3
289    Gentoo    Biscoe     50.0     15.9
290 Chinstrap     Dream     50.0     19.5
291    Gentoo    Biscoe     50.1     15.0
292 Chinstrap     Dream     50.1     17.9
293    Gentoo    Biscoe     50.2     14.3
294 Chinstrap     Dream     50.2     18.8
295 Chinstrap     Dream     50.2     18.7
296 Chinstrap     Dream     50.3     20.0
297    Gentoo    Biscoe     50.4     15.3
298    Gentoo    Biscoe     50.4     15.7
299    Gentoo    Biscoe     50.5     15.9
300    Gentoo    Biscoe     50.5     15.9
301    Gentoo    Biscoe     50.5     15.2
302 Chinstrap     Dream     50.5     19.6
303 Chinstrap     Dream     50.5     18.4
304 Chinstrap     Dream     50.6     19.4
305    Gentoo    Biscoe     50.7     15.0
306 Chinstrap     Dream     50.7     19.7
307    Gentoo    Biscoe     50.8     17.3
308    Gentoo    Biscoe     50.8     15.7
309 Chinstrap     Dream     50.8     18.5
310 Chinstrap     Dream     50.8     19.0
311 Chinstrap     Dream     50.9     19.1
312 Chinstrap     Dream     50.9     17.9
313 Chinstrap     Dream     51.0     18.8
314    Gentoo    Biscoe     51.1     16.3
315    Gentoo    Biscoe     51.1     16.5
316    Gentoo    Biscoe     51.3     14.2
317 Chinstrap     Dream     51.3     19.2
318 Chinstrap     Dream     51.3     18.2
319 Chinstrap     Dream     51.3     19.9
320 Chinstrap     Dream     51.4     19.0
321    Gentoo    Biscoe     51.5     16.3
322 Chinstrap     Dream     51.5     18.7
323 Chinstrap     Dream     51.7     20.3
324 Chinstrap     Dream     51.9     19.5
325 Chinstrap     Dream     52.0     18.1
326 Chinstrap     Dream     52.0     19.0
327 Chinstrap     Dream     52.0     20.7
328    Gentoo    Biscoe     52.1     17.0
329    Gentoo    Biscoe     52.2     17.1
330 Chinstrap     Dream     52.2     18.8
331    Gentoo    Biscoe     52.5     15.6
332 Chinstrap     Dream     52.7     19.8
333 Chinstrap     Dream     52.8     20.0
334    Gentoo    Biscoe     53.4     15.8
335 Chinstrap     Dream     53.5     19.9
336 Chinstrap     Dream     54.2     20.8
337    Gentoo    Biscoe     54.3     15.7
338    Gentoo    Biscoe     55.1     16.0
339 Chinstrap     Dream     55.8     19.8
340    Gentoo    Biscoe     55.9     17.0
341 Chinstrap     Dream     58.0     17.8
342    Gentoo    Biscoe     59.6     17.0
343    Adelie Torgersen       NA       NA
344    Gentoo    Biscoe       NA       NA

Playing with `gt`

penguins |>
  select(species, island, contains("bill")) |>
  sample_n(10) |>
  gt()

species	island	bill_len	bill_dep
Gentoo	Biscoe	44.5	14.3
Adelie	Torgersen	38.6	21.2
Gentoo	Biscoe	45.3	13.7
Chinstrap	Dream	52.8	20.0
Adelie	Torgersen	37.3	20.5
Chinstrap	Dream	43.2	16.6
Gentoo	Biscoe	47.5	14.2
Gentoo	Biscoe	52.2	17.1
Chinstrap	Dream	50.8	19.0
Gentoo	Biscoe	46.1	13.2

Playing with `gt`

penguins |>
  select(species, island, contains("bill")) |>
  sample_n(10) |>
  gt() |>
  cols_align(
    align = "left", 
    columns = c(species, island)) |>
  cols_label(
    species = "Species",
    island = "Island",
    bill_len =  "Bill length (mm)"  ,
    bill_dep = "Bill depth (mm)"
  )

Species	Island	Bill length (mm)	Bill depth (mm)
Adelie	Dream	35.6	17.5
Gentoo	Biscoe	55.9	17.0
Gentoo	Biscoe	43.2	14.5
Adelie	Torgersen	37.2	19.4
Adelie	Torgersen	34.6	17.2
Adelie	Dream	36.0	18.5
Chinstrap	Dream	52.2	18.8
Adelie	Dream	32.1	15.5
Adelie	Dream	37.2	18.1
Adelie	Biscoe	38.1	17.0

Playing with `gt`

penguins |>
  select(species, island, contains("bill")) |>
  sample_n(10) |>
  gt() |>
  cols_align(
    align = "left", 
    columns = c(species, island)) |>
  cols_label(
    species = "Species",
    island = "Island",
    bill_len =  "Length"  ,
    bill_dep = "Depth"
  ) |>
  tab_spanner("Bill dimensions (mm)", contains("bill"))

Species	Island	Bill dimensions (mm)
Species	Island	Length	Depth
Chinstrap	Dream	52.0	18.1
Adelie	Torgersen	35.9	16.6
Adelie	Torgersen	39.7	18.4
Adelie	Torgersen	42.8	18.5
Adelie	Biscoe	37.6	17.0
Adelie	Dream	40.2	17.1
Gentoo	Biscoe	45.5	15.0
Gentoo	Biscoe	46.1	13.2
Chinstrap	Dream	58.0	17.8
Chinstrap	Dream	46.5	17.9

Playing with `gt`

penguins |>
  select(species, island, contains("bill")) |>
  sample_n(10) |>
  gt() |>
  cols_align(
    align = "left", 
    columns = c(species, island)) |>
  cols_label(
    species = "Species",
    island = "Island",
    bill_len =  "Length"  ,
    bill_dep = "Depth"
  ) |>
  tab_spanner("Bill dimensions (mm)", contains("bill")) |> 
  tab_options(column_labels.background.color = "#00A4E1")

Species	Island	Bill dimensions (mm)
Species	Island	Length	Depth
Chinstrap	Dream	49.6	18.2
Adelie	Dream	37.6	19.3
Gentoo	Biscoe	45.4	14.6
Gentoo	Biscoe	51.3	14.2
Gentoo	Biscoe	43.8	13.9
Chinstrap	Dream	52.8	20.0
Adelie	Dream	40.9	18.9
Adelie	Torgersen	NA	NA
Adelie	Torgersen	41.1	17.6
Adelie	Torgersen	35.9	16.6

Playing with `gt`

penguins |>
  select(species, island, contains("bill")) |>
  sample_n(10) |>
  gt() |>
  cols_align(align = "left", columns = c(species, island)) |>
  cols_label(
    species = "Species",
    island = "Island",
    bill_len =  "Length"  ,
    bill_dep = "Depth"
  ) |>
  tab_spanner("Bill dimensions (mm)", contains("bill")) |> 
  tab_options(column_labels.background.color = "#00A4E1") |> 
  tab_style(
    style = cell_text(size = pct(120)),
    locations = cells_body()) |> 
  tab_style(
    style = cell_text(weight = "bold"),
    locations = list(cells_column_labels(),
                     cells_column_spanners()))

Species	Island	Bill dimensions (mm)
Species	Island	Length	Depth
Chinstrap	Dream	51.3	19.9
Gentoo	Biscoe	45.4	14.6
Adelie	Torgersen	36.2	17.2
Adelie	Biscoe	43.2	19.0
Gentoo	Biscoe	46.5	13.5
Adelie	Biscoe	41.1	18.2
Gentoo	Biscoe	45.5	13.9
Adelie	Biscoe	35.5	16.2
Adelie	Dream	36.0	17.1
Chinstrap	Dream	50.2	18.8

Before we stop

We looked into …

Some basic principles
Reviewed on material
Clean up a chart
Formatted numbers

Formatting numbers

Formating numbers

Three types of numbers

Exact numbers

Counted objects

Exact relation

Speed of light

Measured numbers

Data with natural errors

Significant digits

Types of zeros

Significant zeros

Examples

Your turn

How many significant digits?

Solution

How to display numbers

Example numbers

Numbers printed to the console can be deceiving

Common notation systems

Decimal notation

Scientific notation

Engineering notation

Formating the C-style sprintf()

Formating

Examples

Rounding to significant digits

Display of numbers carries a meaning

Generally: Round to three significant digits

Rounding measured data

Tables

Data in tables

Basic conventions

Playing with gt

Playing with gt

Playing with gt

Playing with gt

Playing with gt

Before we stop

We looked into …

Acknowledgements

Formating the C-style `sprintf()`

Playing with `gt`

Playing with `gt`

Playing with `gt`

Playing with `gt`

Playing with `gt`