9  9. tibbles and tribbles

9.1 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")

9.2 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:

9.2.1 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    

9.2.2 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

9.3 Key Differences from data.frames

Tibbles have several important differences from traditional data.frames:

9.3.1 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      2024-01-01    64         81                137
 2 P0002      2024-01-10    36         69                 98
 3 P0003      2024-01-02    41         60                121
 4 P0004      2024-01-31    67         74                129
 5 P0005      2024-01-24    41         80                107
 6 P0006      2024-01-19    94         82                100
 7 P0007      2024-01-19    90         66                143
 8 P0008      2024-01-03    47         85                126
 9 P0009      2024-01-11    91         62                161
10 P0010      2024-01-27    69         74                152
# 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 2024-01-01  64         81                137
2       P0002 2024-01-10  36         69                 98
3       P0003 2024-01-02  41         60                121
4       P0004 2024-01-31  67         74                129
5       P0005 2024-01-24  41         80                107
6       P0006 2024-01-19  94         82                100
7       P0007 2024-01-19  90         66                143
8       P0008 2024-01-03  47         85                126
9       P0009 2024-01-11  91         62                161
10      P0010 2024-01-27  69         74                152
11      P0011 2024-01-06  46         71                118
12      P0012 2024-01-10  54         89                119
13      P0013 2024-01-22  59         78                108
14      P0014 2024-01-07  78         93                112
15      P0015 2024-01-03  37         75                129
16      P0016 2024-01-16  53         80                115
17      P0017 2024-01-16  70         71                141
18      P0018 2024-01-02  38         67                129
19      P0019 2024-01-03  94         78                134
20      P0020 2024-01-17  35         82                121
21      P0021 2024-01-27  34         88                 98
22      P0022 2024-01-16  48         86                129
23      P0023 2024-01-05  68         81                154
24      P0024 2024-01-14  74         64                107
25      P0025 2024-01-25  82         63                111
   blood_pressure_dia temperature oxygen_saturation
1                  86        98.2               100
2                  66        98.5                97
3                  68        98.1                96
4                  63        98.8                98
5                  74        99.2                97
6                  84        98.7                98
7                  81        98.2                98
8                  66        99.6                98
9                  74        98.6                97
10                 70        98.6                97
11                 90        98.3                97
12                 80        98.3                98
13                101        99.4                97
14                 77        98.8                97
15                 97        99.0                97
16                 81        97.7                97
17                 94        99.0               100
18                 83        99.1                99
19                 79        98.5                99
20                 80        98.7                98
21                 77        98.5                97
22                102        98.5                98
23                 83        97.6               100
24                 83        99.2               102
25                 79        98.1                97
   cholesterol glucose weight_kg height_cm
1          140     120      70.6       181
2          194      89     101.7       158
3           94      94      61.8       173
4          207     123      73.0       174
5          197      90      53.5       171
6          183     109      36.5       159
7          157      87      84.4       163
8          156      82      79.7       168
9          185      82      69.1       173
10         205     124      67.7       169
11         137      35      82.5       180
12         187      91     101.5       165
13         176      93      81.9       176
14         132      96      40.1       173
15         192      78      68.2       181
16         247      93      46.8       182
17         194     104      79.3       171
18         166      83      81.6       159
19         161     116      78.1       162
20         189     114      72.4       167
21         225     101      67.2       172
22         139     112      65.9       157
23         174     105      88.2       173
24         151     123      92.4       171
25         194     114      69.4       181

9.4 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      2024-01-01    64         81                137
 2 P0002      2024-01-10    36         69                 98
 3 P0003      2024-01-02    41         60                121
 4 P0004      2024-01-31    67         74                129
 5 P0005      2024-01-24    41         80                107
 6 P0006      2024-01-19    94         82                100
 7 P0007      2024-01-19    90         66                143
 8 P0008      2024-01-03    47         85                126
 9 P0009      2024-01-11    91         62                161
10 P0010      2024-01-27    69         74                152
11 P0011      2024-01-06    46         71                118
12 P0012      2024-01-10    54         89                119
13 P0013      2024-01-22    59         78                108
14 P0014      2024-01-07    78         93                112
15 P0015      2024-01-03    37         75                129
16 P0016      2024-01-16    53         80                115
17 P0017      2024-01-16    70         71                141
18 P0018      2024-01-02    38         67                129
19 P0019      2024-01-03    94         78                134
20 P0020      2024-01-17    35         82                121
# 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      2024-01-01    64         81                137
 2 P0002      2024-01-10    36         69                 98
 3 P0003      2024-01-02    41         60                121
 4 P0004      2024-01-31    67         74                129
 5 P0005      2024-01-24    41         80                107
 6 P0006      2024-01-19    94         82                100
 7 P0007      2024-01-19    90         66                143
 8 P0008      2024-01-03    47         85                126
 9 P0009      2024-01-11    91         62                161
10 P0010      2024-01-27    69         74                152
11 P0011      2024-01-06    46         71                118
12 P0012      2024-01-10    54         89                119
13 P0013      2024-01-22    59         78                108
14 P0014      2024-01-07    78         93                112
15 P0015      2024-01-03    37         75                129
16 P0016      2024-01-16    53         80                115
17 P0017      2024-01-16    70         71                141
18 P0018      2024-01-02    38         67                129
19 P0019      2024-01-03    94         78                134
20 P0020      2024-01-17    35         82                121
21 P0021      2024-01-27    34         88                 98
22 P0022      2024-01-16    48         86                129
23 P0023      2024-01-05    68         81                154
24 P0024      2024-01-14    74         64                107
25 P0025      2024-01-25    82         63                111
# ℹ 7 more variables: blood_pressure_dia <dbl>,
#   temperature <dbl>, oxygen_saturation <dbl>,
#   cholesterol <dbl>, glucose <dbl>, weight_kg <dbl>,
#   height_cm <dbl>

9.4.1 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      2024-01-01    64         81                137
 2 P0002      2024-01-10    36         69                 98
 3 P0003      2024-01-02    41         60                121
 4 P0004      2024-01-31    67         74                129
 5 P0005      2024-01-24    41         80                107
 6 P0006      2024-01-19    94         82                100
 7 P0007      2024-01-19    90         66                143
 8 P0008      2024-01-03    47         85                126
 9 P0009      2024-01-11    91         62                161
10 P0010      2024-01-27    69         74                152
# 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      2024-01-01    64         81                137                 86        98.2               100         140     120      70.6       181
 2 P0002      2024-01-10    36         69                 98                 66        98.5                97         194      89     102.        158
 3 P0003      2024-01-02    41         60                121                 68        98.1                96          94      94      61.8       173
 4 P0004      2024-01-31    67         74                129                 63        98.8                98         207     123      73         174
 5 P0005      2024-01-24    41         80                107                 74        99.2                97         197      90      53.5       171
 6 P0006      2024-01-19    94         82                100                 84        98.7                98         183     109      36.5       159
 7 P0007      2024-01-19    90         66                143                 81        98.2                98         157      87      84.4       163
 8 P0008      2024-01-03    47         85                126                 66        99.6                98         156      82      79.7       168
 9 P0009      2024-01-11    91         62                161                 74        98.6                97         185      82      69.1       173
10 P0010      2024-01-27    69         74                152                 70        98.6                97         205     124      67.7       169
# ℹ 15 more rows

9.4.2 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    

9.5 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    

9.6 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

9.7 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"

9.8 Other differences between tibbles and dataframes

9.8.1 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