Reorders the Contents of a Vector

Shuffle the order of a vector around using natural language statements.

moveMe(invec, movecommand)

Arguments

invec	The input vector
movecommand	The command that describes how you want to shuffle the vector. See Details.

Value

A vector.

Details

This can be a useful function for reordering the columns of a data.frame or data.table in a convenient manner. In such cases, the invec would be names(your_data_frame). When using data.tables, remember to use setcolorder to avoid copying.

The movecommand argument is specified in the form of "a, b before f". The positions to move are:

• first: move the specified items to the first postion.

• last: move the specified items to the last position.

• before: move the specified items before the value mentioned.

• after: move the specified items after the value mentioned.

Multiples are allowed:

• Specify multiple values to be moved by separating them with a comma.

• Chain multiple move commands by separating them with a semicolon.

References

http://stackoverflow.com/a/18420673/1270695

Author

Ananda Mahto

Examples

myvec <- letters[1:10]
myvec
#>  [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"
moveMe(myvec, "a last; b, e, g before d; c first; h after j")
#>  [1] "c" "b" "e" "g" "d" "f" "i" "j" "h" "a"

x <- names(mtcars)
x
#>  [1] "mpg"  "cyl"  "disp" "hp"   "drat" "wt"   "qsec" "vs"   "am"   "gear"
#> [11] "carb"
moveMe(x, "hp first; cyl after drat; vs, am, gear before mpg; wt last")
#>  [1] "hp"   "vs"   "am"   "gear" "mpg"  "disp" "drat" "cyl"  "qsec" "carb"
#> [11] "wt"