Show the head and tail of an object

Show both the head and tail of an R object

ht(x, n = 6L, m = n, returnList = FALSE, ...)

Arguments

x

The object to show

n

The number of elements to list for the head

m

The number of elements to list for the tail

returnList

Logical. Should the result be returned as a list

...

additional arguments passed to functions (not used at the moment)

Value

NULL unless returnList is set to TRUE in which case a list is returned

Details

This function does no error checking and it is up to the user to ensure that the input is indeed symmetric, positive-definite, and a matrix.

Author

Claus Ekstrom, claus@rprimer.dk.

Examples

ht(trees)
#>   Girth Height Volume
#> 1   8.3     70   10.3
#> 2   8.6     65   10.3
#> 3   8.8     63   10.2
#> 4  10.5     72   16.4
#> 5  10.7     81   18.8
#> 6  10.8     83   19.7
#> ...
#>    Girth Height Volume
#> 26  17.3     81   55.4
#> 27  17.5     82   55.7
#> 28  17.9     80   58.3
#> 29  18.0     80   51.5
#> 30  18.0     80   51.0
#> 31  20.6     87   77.0
ht(diag(20))
#>      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14]
#> [1,]    1    0    0    0    0    0    0    0    0     0     0     0     0     0
#> [2,]    0    1    0    0    0    0    0    0    0     0     0     0     0     0
#> [3,]    0    0    1    0    0    0    0    0    0     0     0     0     0     0
#> [4,]    0    0    0    1    0    0    0    0    0     0     0     0     0     0
#> [5,]    0    0    0    0    1    0    0    0    0     0     0     0     0     0
#> [6,]    0    0    0    0    0    1    0    0    0     0     0     0     0     0
#>      [,15] [,16] [,17] [,18] [,19] [,20]
#> [1,]     0     0     0     0     0     0
#> [2,]     0     0     0     0     0     0
#> [3,]     0     0     0     0     0     0
#> [4,]     0     0     0     0     0     0
#> [5,]     0     0     0     0     0     0
#> [6,]     0     0     0     0     0     0
#> ...
#>       [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13]
#> [15,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#> [16,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#> [17,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#> [18,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#> [19,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#> [20,]    0    0    0    0    0    0    0    0    0     0     0     0     0
#>       [,14] [,15] [,16] [,17] [,18] [,19] [,20]
#> [15,]     0     1     0     0     0     0     0
#> [16,]     0     0     1     0     0     0     0
#> [17,]     0     0     0     1     0     0     0
#> [18,]     0     0     0     0     1     0     0
#> [19,]     0     0     0     0     0     1     0
#> [20,]     0     0     0     0     0     0     1
ht(1:20)
#> [1] 1 2 3 4 5 6
#> ...
#> [1] 15 16 17 18 19 20
ht(1:20, returnList=TRUE)
#> $head
#> [1] 1 2 3 4 5 6
#> 
#> $tail
#> [1] 15 16 17 18 19 20
#>