10  10. tibbles and tribbles

10.1 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")

10.2 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:

10.2.1 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    

10.2.2 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

10.3 Key Differences from data.frames

Tibbles have several important differences from traditional data.frames:

10.3.1 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      2024-01-09    26         83                144
 2 P0002      2024-01-08    76         70                109
 3 P0003      2024-01-30    82         68                113
 4 P0004      2024-01-06    82         93                122
 5 P0005      2024-01-18    51         78                119
 6 P0006      2024-01-13    90         85                111
 7 P0007      2024-01-24    41         48                122
 8 P0008      2024-01-21    26         67                 99
 9 P0009      2024-01-14    21         80                120
10 P0010      2024-01-19    64         78                132
# 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 2024-01-09  26         83                144
2       P0002 2024-01-08  76         70                109
3       P0003 2024-01-30  82         68                113
4       P0004 2024-01-06  82         93                122
5       P0005 2024-01-18  51         78                119
6       P0006 2024-01-13  90         85                111
7       P0007 2024-01-24  41         48                122
8       P0008 2024-01-21  26         67                 99
9       P0009 2024-01-14  21         80                120
10      P0010 2024-01-19  64         78                132
11      P0011 2024-01-02  30        100                139
12      P0012 2024-01-29  22         68                129
13      P0013 2024-01-21  41         70                115
14      P0014 2024-01-18  75         94                 93
15      P0015 2024-01-17  71         58                 97
16      P0016 2024-01-04  37         80                125
17      P0017 2024-01-07  91         87                119
18      P0018 2024-01-23  87         54                115
19      P0019 2024-01-02  51         73                100
20      P0020 2024-01-04  84         88                124
21      P0021 2024-01-04  76         71                114
22      P0022 2024-01-14  34         71                137
23      P0023 2024-01-07  73         64                108
24      P0024 2024-01-05  65         73                146
25      P0025 2024-01-28  82         95                128
   blood_pressure_dia temperature oxygen_saturation
1                  65        98.3                98
2                  77        98.7                97
3                  86        99.0                98
4                  67        98.5                93
5                  72        99.1                99
6                  80        98.4               100
7                  63        98.4               101
8                  57        99.3                97
9                  83        98.6                99
10                 90        98.8                96
11                 74        99.2               100
12                 70        98.2                98
13                 70        98.2                99
14                 78        98.7               100
15                 80        98.6               101
16                 77        97.4                99
17                 79        98.4                98
18                 77        99.0                96
19                 63        98.9                99
20                 95        98.2               100
21                 88        98.5                99
22                 90        98.9               100
23                 97        98.3               100
24                 89        98.3               100
25                 76        97.9                98
   cholesterol glucose weight_kg height_cm
1          230     144      73.5       173
2          162     107      97.0       174
3          197     124      89.4       173
4          201     105      66.1       166
5          186     131      72.4       151
6          170     104      62.8       178
7          179      98      83.2       180
8          170      94      60.2       148
9          150      94      71.5       186
10         182     122      88.5       185
11         212      75      76.3       179
12         164     107      71.6       172
13         228      94      84.7       167
14         229     118      78.1       159
15         222      99     100.4       187
16         165      58      52.3       163
17         165     123      96.3       153
18         169     115      66.9       171
19         185      95      57.6       175
20         183     127      40.2       177
21         236     106      70.0       177
22         225     115      75.0       149
23         113      98      78.0       179
24         215      65      36.7       177
25         195      87      70.3       191

10.4 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      2024-01-09    26         83                144
 2 P0002      2024-01-08    76         70                109
 3 P0003      2024-01-30    82         68                113
 4 P0004      2024-01-06    82         93                122
 5 P0005      2024-01-18    51         78                119
 6 P0006      2024-01-13    90         85                111
 7 P0007      2024-01-24    41         48                122
 8 P0008      2024-01-21    26         67                 99
 9 P0009      2024-01-14    21         80                120
10 P0010      2024-01-19    64         78                132
11 P0011      2024-01-02    30        100                139
12 P0012      2024-01-29    22         68                129
13 P0013      2024-01-21    41         70                115
14 P0014      2024-01-18    75         94                 93
15 P0015      2024-01-17    71         58                 97
16 P0016      2024-01-04    37         80                125
17 P0017      2024-01-07    91         87                119
18 P0018      2024-01-23    87         54                115
19 P0019      2024-01-02    51         73                100
20 P0020      2024-01-04    84         88                124
# 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      2024-01-09    26         83                144
 2 P0002      2024-01-08    76         70                109
 3 P0003      2024-01-30    82         68                113
 4 P0004      2024-01-06    82         93                122
 5 P0005      2024-01-18    51         78                119
 6 P0006      2024-01-13    90         85                111
 7 P0007      2024-01-24    41         48                122
 8 P0008      2024-01-21    26         67                 99
 9 P0009      2024-01-14    21         80                120
10 P0010      2024-01-19    64         78                132
11 P0011      2024-01-02    30        100                139
12 P0012      2024-01-29    22         68                129
13 P0013      2024-01-21    41         70                115
14 P0014      2024-01-18    75         94                 93
15 P0015      2024-01-17    71         58                 97
16 P0016      2024-01-04    37         80                125
17 P0017      2024-01-07    91         87                119
18 P0018      2024-01-23    87         54                115
19 P0019      2024-01-02    51         73                100
20 P0020      2024-01-04    84         88                124
21 P0021      2024-01-04    76         71                114
22 P0022      2024-01-14    34         71                137
23 P0023      2024-01-07    73         64                108
24 P0024      2024-01-05    65         73                146
25 P0025      2024-01-28    82         95                128
# ℹ 7 more variables: blood_pressure_dia <dbl>,
#   temperature <dbl>, oxygen_saturation <dbl>,
#   cholesterol <dbl>, glucose <dbl>, weight_kg <dbl>,
#   height_cm <dbl>

10.4.1 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      2024-01-09    26         83                144
 2 P0002      2024-01-08    76         70                109
 3 P0003      2024-01-30    82         68                113
 4 P0004      2024-01-06    82         93                122
 5 P0005      2024-01-18    51         78                119
 6 P0006      2024-01-13    90         85                111
 7 P0007      2024-01-24    41         48                122
 8 P0008      2024-01-21    26         67                 99
 9 P0009      2024-01-14    21         80                120
10 P0010      2024-01-19    64         78                132
# 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      2024-01-09    26         83                144                 65        98.3                98         230     144      73.5       173
 2 P0002      2024-01-08    76         70                109                 77        98.7                97         162     107      97         174
 3 P0003      2024-01-30    82         68                113                 86        99                  98         197     124      89.4       173
 4 P0004      2024-01-06    82         93                122                 67        98.5                93         201     105      66.1       166
 5 P0005      2024-01-18    51         78                119                 72        99.1                99         186     131      72.4       151
 6 P0006      2024-01-13    90         85                111                 80        98.4               100         170     104      62.8       178
 7 P0007      2024-01-24    41         48                122                 63        98.4               101         179      98      83.2       180
 8 P0008      2024-01-21    26         67                 99                 57        99.3                97         170      94      60.2       148
 9 P0009      2024-01-14    21         80                120                 83        98.6                99         150      94      71.5       186
10 P0010      2024-01-19    64         78                132                 90        98.8                96         182     122      88.5       185
# ℹ 15 more rows

10.4.2 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    

10.5 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    

10.6 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

10.7 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"

10.8 Other differences between tibbles and dataframes

10.8.1 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