13  13. tibbles and tribbles

13.1 Introduction to Tibbles

# Tibbles are part of the tibble package, which is included in tidyverse
# You can install/load tibble directly
if(!require(tibble)) {install.packages("tibble");require(tibble);}
Loading required package: tibble
# For more info see:
#
# help(package="tibble")

13.2 What are Tibbles?

Tibbles are a modern reimagining of R’s traditional data.frame. They are designed to make working with data frames easier and more consistent. Here’s how to create a basic tibble:

13.2.1 tibble() function is similar to data.frame() function

Create a tibble with the tibble function. It’s use is very similar to how you would use the data.frame function to create a dataframe (we’re assuming that you’re familiar with creating dataframes in R)

# Create a tibble directly
my_tibble = tibble(
  x = 1:3,
  y = letters[1:3],
  z = LETTERS[1:3]
)
my_tibble
# A tibble: 3 × 3
      x y     z    
  <int> <chr> <chr>
1     1 a     A    
2     2 b     B    
3     3 c     C    

13.2.2 as_tibble() to convert data.frame or matrix to a tibble

# convert a dataframe to a tibble

df = data.frame(
  numbers = 1:3,
  letters = c("a", "b", "c")
)

tbl = as_tibble(df)
tbl

# convert a matrix to a tibble

mat = matrix(seq(10,120,by=10), nrow=3,ncol = 4) 
tbl = as_tibble(mat)
tbl

13.3 Key Differences from data.frames

Tibbles have several important differences from traditional data.frames:

13.3.1 Default Printing Behavior

# Create a wide tibble with many columns 25 rows.

health_data = tibble(
  patient_id = sprintf("P%04d", 1:25),
  admit_date = as.Date("2024-01-01") + sample(0:30, 25, replace = TRUE),
  age = sample(18:95, 25, replace = TRUE),
  heart_rate = round(rnorm(25, 75, 10)),
  blood_pressure_sys = round(rnorm(25, 120, 15)),
  blood_pressure_dia = round(rnorm(25, 80, 10)),
  temperature = round(rnorm(25, 98.6, 0.5), 1),
  oxygen_saturation = round(rnorm(25, 98, 2)),
  cholesterol = round(rnorm(25, 190, 30)),
  glucose = round(rnorm(25, 100, 20)),
  weight_kg = round(rnorm(25, 70, 15), 1),
  height_cm = round(rnorm(25, 170, 10))
)

# Tibbles show only the first 10 rows by default
# and only columns that fit on screen
health_data
# A tibble: 25 × 12
   patient_id admit_date   age heart_rate blood_pressure_sys
   <chr>      <date>     <int>      <dbl>              <dbl>
 1 P0001      2024-01-25    73         71                113
 2 P0002      2024-01-10    24         95                130
 3 P0003      2024-01-12    32         74                126
 4 P0004      2024-01-13    49         80                 98
 5 P0005      2024-01-01    95         74                116
 6 P0006      2024-01-02    32         79                133
 7 P0007      2024-01-24    26         78                119
 8 P0008      2024-01-06    57         77                102
 9 P0009      2024-01-06    79         70                132
10 P0010      2024-01-02    82         81                136
# ℹ 15 more rows
# ℹ 7 more variables: blood_pressure_dia <dbl>,
#   temperature <dbl>, oxygen_saturation <dbl>,
#   cholesterol <dbl>, glucose <dbl>, weight_kg <dbl>,
#   height_cm <dbl>
# Compare to data.frame which tries to print everything
as.data.frame(health_data)
   patient_id admit_date age heart_rate blood_pressure_sys
1       P0001 2024-01-25  73         71                113
2       P0002 2024-01-10  24         95                130
3       P0003 2024-01-12  32         74                126
4       P0004 2024-01-13  49         80                 98
5       P0005 2024-01-01  95         74                116
6       P0006 2024-01-02  32         79                133
7       P0007 2024-01-24  26         78                119
8       P0008 2024-01-06  57         77                102
9       P0009 2024-01-06  79         70                132
10      P0010 2024-01-02  82         81                136
11      P0011 2024-01-05  20         58                107
12      P0012 2024-01-26  42         82                108
13      P0013 2024-01-28  68         82                135
14      P0014 2024-01-01  75         66                126
15      P0015 2024-01-05  55         81                 87
16      P0016 2024-01-16  36         79                146
17      P0017 2024-01-26  29         87                135
18      P0018 2024-01-06  61         79                115
19      P0019 2024-01-03  19         72                107
20      P0020 2024-01-26  89         82                125
21      P0021 2024-01-16  67         76                140
22      P0022 2024-01-23  83         83                118
23      P0023 2024-01-31  50         80                122
24      P0024 2024-01-19  25         67                133
25      P0025 2024-01-05  89         77                128
   blood_pressure_dia temperature oxygen_saturation
1                  83        98.3                96
2                  77        99.3                97
3                  82        98.7                98
4                  80        98.9                96
5                  76        98.5                98
6                  82        98.8                99
7                  84        99.4                99
8                  79        98.4               101
9                 101        98.8                99
10                 75        98.7                95
11                 91        99.3                99
12                 83        98.4                98
13                 65        98.8               101
14                 74        99.0                97
15                 96        98.4                99
16                 88        98.5               101
17                 95        99.1                99
18                 72        98.5                97
19                 89        99.0                96
20                 66        98.9                99
21                 73        98.3               100
22                 87        98.7               100
23                 72        98.0                97
24                 80        98.3                97
25                 93        97.9                99
   cholesterol glucose weight_kg height_cm
1          187      86      83.8       170
2          126     110      75.1       180
3          134     103      59.7       155
4          112     101      67.5       167
5          163      99      82.1       166
6          167      99      78.4       176
7          205      80      58.2       167
8          211     113      69.3       177
9          142      97      36.3       173
10         187     137      79.2       164
11         233     131      87.4       161
12         244      81      72.7       166
13         201     118      64.7       163
14         183     110      69.1       171
15         226      93      68.6       169
16         230      90      51.8       156
17         161      58      56.8       182
18         201      80      82.1       184
19         211     137      61.3       178
20         186     114      84.5       193
21         117      96      90.0       179
22         178      76      80.2       177
23         173     108      60.6       179
24         206     118      54.7       167
25         259     136      67.0       164

13.4 Printing More Rows/Columns of a Tibble

# By default, print() shows 10 rows. Use n= to show more rows
print(health_data, n = 20)  # Shows 20 rows
# A tibble: 25 × 12
   patient_id admit_date   age heart_rate blood_pressure_sys
   <chr>      <date>     <int>      <dbl>              <dbl>
 1 P0001      2024-01-25    73         71                113
 2 P0002      2024-01-10    24         95                130
 3 P0003      2024-01-12    32         74                126
 4 P0004      2024-01-13    49         80                 98
 5 P0005      2024-01-01    95         74                116
 6 P0006      2024-01-02    32         79                133
 7 P0007      2024-01-24    26         78                119
 8 P0008      2024-01-06    57         77                102
 9 P0009      2024-01-06    79         70                132
10 P0010      2024-01-02    82         81                136
11 P0011      2024-01-05    20         58                107
12 P0012      2024-01-26    42         82                108
13 P0013      2024-01-28    68         82                135
14 P0014      2024-01-01    75         66                126
15 P0015      2024-01-05    55         81                 87
16 P0016      2024-01-16    36         79                146
17 P0017      2024-01-26    29         87                135
18 P0018      2024-01-06    61         79                115
19 P0019      2024-01-03    19         72                107
20 P0020      2024-01-26    89         82                125
# ℹ 5 more rows
# ℹ 7 more variables: blood_pressure_dia <dbl>,
#   temperature <dbl>, oxygen_saturation <dbl>,
#   cholesterol <dbl>, glucose <dbl>, weight_kg <dbl>,
#   height_cm <dbl>
# To see all rows
print(health_data, n = Inf)
# A tibble: 25 × 12
   patient_id admit_date   age heart_rate blood_pressure_sys
   <chr>      <date>     <int>      <dbl>              <dbl>
 1 P0001      2024-01-25    73         71                113
 2 P0002      2024-01-10    24         95                130
 3 P0003      2024-01-12    32         74                126
 4 P0004      2024-01-13    49         80                 98
 5 P0005      2024-01-01    95         74                116
 6 P0006      2024-01-02    32         79                133
 7 P0007      2024-01-24    26         78                119
 8 P0008      2024-01-06    57         77                102
 9 P0009      2024-01-06    79         70                132
10 P0010      2024-01-02    82         81                136
11 P0011      2024-01-05    20         58                107
12 P0012      2024-01-26    42         82                108
13 P0013      2024-01-28    68         82                135
14 P0014      2024-01-01    75         66                126
15 P0015      2024-01-05    55         81                 87
16 P0016      2024-01-16    36         79                146
17 P0017      2024-01-26    29         87                135
18 P0018      2024-01-06    61         79                115
19 P0019      2024-01-03    19         72                107
20 P0020      2024-01-26    89         82                125
21 P0021      2024-01-16    67         76                140
22 P0022      2024-01-23    83         83                118
23 P0023      2024-01-31    50         80                122
24 P0024      2024-01-19    25         67                133
25 P0025      2024-01-05    89         77                128
# ℹ 7 more variables: blood_pressure_dia <dbl>,
#   temperature <dbl>, oxygen_saturation <dbl>,
#   cholesterol <dbl>, glucose <dbl>, weight_kg <dbl>,
#   height_cm <dbl>

13.4.1 Controlling Column Width

# width argument to print specifies the number of characters that should
# be printed in the widest row. In effect, this limits the number of columns
# being output to those columns that fit in the specified width.
print(health_data, width = 75)
# A tibble: 25 × 12
   patient_id admit_date   age heart_rate blood_pressure_sys
   <chr>      <date>     <int>      <dbl>              <dbl>
 1 P0001      2024-01-25    73         71                113
 2 P0002      2024-01-10    24         95                130
 3 P0003      2024-01-12    32         74                126
 4 P0004      2024-01-13    49         80                 98
 5 P0005      2024-01-01    95         74                116
 6 P0006      2024-01-02    32         79                133
 7 P0007      2024-01-24    26         78                119
 8 P0008      2024-01-06    57         77                102
 9 P0009      2024-01-06    79         70                132
10 P0010      2024-01-02    82         81                136
# ℹ 15 more rows
# ℹ 7 more variables: blood_pressure_dia <dbl>, temperature <dbl>,
#   oxygen_saturation <dbl>, cholesterol <dbl>, glucose <dbl>,
#   weight_kg <dbl>, height_cm <dbl>
# Show all columns by setting width to Inf
print(health_data, width = Inf)
# A tibble: 25 × 12
   patient_id admit_date   age heart_rate blood_pressure_sys blood_pressure_dia temperature oxygen_saturation cholesterol glucose weight_kg height_cm
   <chr>      <date>     <int>      <dbl>              <dbl>              <dbl>       <dbl>             <dbl>       <dbl>   <dbl>     <dbl>     <dbl>
 1 P0001      2024-01-25    73         71                113                 83        98.3                96         187      86      83.8       170
 2 P0002      2024-01-10    24         95                130                 77        99.3                97         126     110      75.1       180
 3 P0003      2024-01-12    32         74                126                 82        98.7                98         134     103      59.7       155
 4 P0004      2024-01-13    49         80                 98                 80        98.9                96         112     101      67.5       167
 5 P0005      2024-01-01    95         74                116                 76        98.5                98         163      99      82.1       166
 6 P0006      2024-01-02    32         79                133                 82        98.8                99         167      99      78.4       176
 7 P0007      2024-01-24    26         78                119                 84        99.4                99         205      80      58.2       167
 8 P0008      2024-01-06    57         77                102                 79        98.4               101         211     113      69.3       177
 9 P0009      2024-01-06    79         70                132                101        98.8                99         142      97      36.3       173
10 P0010      2024-01-02    82         81                136                 75        98.7                95         187     137      79.2       164
# ℹ 15 more rows

13.4.2 Row Names

# data.frames can have row names
df_rownames = data.frame(
  x = 1:3,
  y = letters[1:3],
  row.names = c("row1", "row2", "row3")
)
df_rownames
     x y
row1 1 a
row2 2 b
row3 3 c
# Tibbles don't support row names
# If you convert a data.frame with row names to a tibble,
# the row names become a regular column called 'rowname'
as_tibble(df_rownames, rownames = "id")
# A tibble: 3 × 3
  id        x y    
  <chr> <int> <chr>
1 row1      1 a    
2 row2      2 b    
3 row3      3 c    

13.5 Creating Tibbles

You can create tibbles in several ways:

# Using tibble()
t1 = tibble(
  x = 1:5,
  y = x * 2,  # Note: you can refer to columns created earlier
  z = letters[1:5]
)
t1
# A tibble: 5 × 3
      x     y z    
  <int> <dbl> <chr>
1     1     2 a    
2     2     4 b    
3     3     6 c    
4     4     8 d    
5     5    10 e    

13.6 creating tibble row by row using tribbles

While reading the raw code for creating a dataframe or a tibble, it can be challenging to visualize what the actual dataframe/tibble will look like. This is because when typing the data into the code, each column is typed horrizontally instead of vertically. For example:

# Using tribble() for transposed input
# Useful for small, manual data entry
stuff = tribble(
  col1 = c("a",  "b",   "c"),
  col2 = c( 1,    2,     3)
  col3 = c(TRUE, FALSE, TRUE))

# The code above lays out columns horizontally. 
# The actual dataframe displays columns vertically.
stuff

A “tribble” (i.e. TRansposed tIBBLE) is just a different way of typing the code that becomes a tibble. Each column heading is prefixed with a tilde (~). The columns can be laid out vertically in the code, making the code much more readable. See the example below.

# Using tribble() for transposed input
# Useful for small, manual data entry
stuff = tribble(
  ~col1, ~col2, ~col3,
  "a",   1,     TRUE,
  "b",   2,     FALSE,
  "c",   3,     TRUE
)

# The following looks much more similar to the code that created it.
stuff

13.7 Converting Between Tibbles and data.frames

# Convert data.frame to tibble
df = data.frame(
  x = 1:3,
  y = letters[1:3]
)
tbl = as_tibble(df)

# Convert tibble back to data.frame
df_again = as.data.frame(tbl)

# Check classes
class(tbl)
[1] "tbl_df"     "tbl"        "data.frame"
class(df_again)
[1] "data.frame"

13.8 Other differences between tibbles and dataframes

13.8.1 Variable Names and Subsetting

# data.frames modify non-syntactic names
df_names = data.frame(
  `1` = 1:3,
  `2+2` = 4:6,
  check.names = TRUE  # default behavior
)
names(df_names)  # Names are modified
[1] "X1"   "X2.2"
# Tibbles preserve original names
tbl_names = tibble(
  `1` = 1:3,
  `2+2` = 4:6
)
names(tbl_names)  # Original names kept
[1] "1"   "2+2"
# Subsetting differences
# data.frame allows partial matching of variable names
df = data.frame(numbers = 1:3, letters = c("a", "b", "c"))
df$num  # Partial matching works
[1] 1 2 3
# Tibbles require exact matching
tbl = tibble(numbers = 1:3, letters = c("a", "b", "c"))
try(tbl$num)  # This will raise an error
Warning: Unknown or uninitialised column: `num`.
NULL