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Print head and tail of a data frame or vector with indices

Source: R/general_ht.R
ht.Rd

Prints the first and last few rows of a data frame or elements of a vector, displaying row numbers for data frames or indices for vectors in a style similar to data.table. Useful for quickly inspecting the structure and contents of large data frames or vectors, with explicit row or index numbers.

Usage

ht(data = NULL, n_rows = 5L)

Arguments

data

A data frame or vector (numeric, character, or other atomic types). This parameter cannot be NULL.

n_rows

Integer. Number of rows (for data frames) or elements (for vectors) to print from both the head and tail. Defaults to 5.

Value

The function is used for its side effect (printing) and returns invisible(NULL).

Author

Ahmed El-Gabbas

Examples

# Data frame examples

ht(mtcars)
#>       mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>     <num> <num> <num> <num> <num> <num> <num> <num> <num> <num> <num>
#>  1:  21.0     6 160.0   110  3.90 2.620 16.46     0     1     4     4
#>  2:  21.0     6 160.0   110  3.90 2.875 17.02     0     1     4     4
#>  3:  22.8     4 108.0    93  3.85 2.320 18.61     1     1     4     1
#>  4:  21.4     6 258.0   110  3.08 3.215 19.44     1     0     3     1
#>  5:  18.7     8 360.0   175  3.15 3.440 17.02     0     0     3     2
#> ---                                                                  
#> 28:  30.4     4  95.1   113  3.77 1.513 16.90     1     1     5     2
#> 29:  15.8     8 351.0   264  4.22 3.170 14.50     0     1     5     4
#> 30:  19.7     6 145.0   175  3.62 2.770 15.50     0     1     5     6
#> 31:  15.0     8 301.0   335  3.54 3.570 14.60     0     1     5     8
#> 32:  21.4     4 121.0   109  4.11 2.780 18.60     1     1     4     2

ht(data = mtcars, n_rows = 2)
#>       mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>     <num> <num> <num> <num> <num> <num> <num> <num> <num> <num> <num>
#>  1:  21.0     6   160   110  3.90 2.620 16.46     0     1     4     4
#>  2:  21.0     6   160   110  3.90 2.875 17.02     0     1     4     4
#> ---                                                                  
#> 31:  15.0     8   301   335  3.54 3.570 14.60     0     1     5     8
#> 32:  21.4     4   121   109  4.11 2.780 18.60     1     1     4     2

ht(data = mtcars, n_rows = 6)
#>       mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>     <num> <num> <num> <num> <num> <num> <num> <num> <num> <num> <num>
#>  1:  21.0     6 160.0   110  3.90 2.620 16.46     0     1     4     4
#>  2:  21.0     6 160.0   110  3.90 2.875 17.02     0     1     4     4
#>  3:  22.8     4 108.0    93  3.85 2.320 18.61     1     1     4     1
#>  4:  21.4     6 258.0   110  3.08 3.215 19.44     1     0     3     1
#>  5:  18.7     8 360.0   175  3.15 3.440 17.02     0     0     3     2
#>  6:  18.1     6 225.0   105  2.76 3.460 20.22     1     0     3     1
#> ---                                                                  
#> 27:  26.0     4 120.3    91  4.43 2.140 16.70     0     1     5     2
#> 28:  30.4     4  95.1   113  3.77 1.513 16.90     1     1     5     2
#> 29:  15.8     8 351.0   264  4.22 3.170 14.50     0     1     5     4
#> 30:  19.7     6 145.0   175  3.62 2.770 15.50     0     1     5     6
#> 31:  15.0     8 301.0   335  3.54 3.570 14.60     0     1     5     8
#> 32:  21.4     4 121.0   109  4.11 2.780 18.60     1     1     4     2

# -------------------------------------------

# Vector examples

ht(1:100)
#>      value
#>      <int>
#>   1:     1
#>   2:     2
#>   3:     3
#>   4:     4
#>   5:     5
#>  ---      
#>  96:    96
#>  97:    97
#>  98:    98
#>  99:    99
#> 100:   100

ht(letters)
#>      value
#>     <char>
#>  1:      a
#>  2:      b
#>  3:      c
#>  4:      d
#>  5:      e
#> ---       
#> 22:      v
#> 23:      w
#> 24:      x
#> 25:      y
#> 26:      z

colour_vect <- colours()
colour_vect <- seq_along(colour_vect) %>%
  stats::setNames(paste0("colour:", colour_vect))
head(colour_vect)
#>         colour:white     colour:aliceblue  colour:antiquewhite 
#>                    1                    2                    3 
#> colour:antiquewhite1 colour:antiquewhite2 colour:antiquewhite3 
#>                    4                    5                    6 
ht(colour_vect)
#>                      name value
#>                    <char> <int>
#>   1:         colour:white     1
#>   2:     colour:aliceblue     2
#>   3:  colour:antiquewhite     3
#>   4: colour:antiquewhite1     4
#>   5: colour:antiquewhite2     5
#>  ---                           
#> 653:       colour:yellow1   653
#> 654:       colour:yellow2   654
#> 655:       colour:yellow3   655
#> 656:       colour:yellow4   656
#> 657:   colour:yellowgreen   657