take -- Take some elements from a list or sequence.

Synopsis

• Usage:

  take(L, i)

  take(L, {j,k})

  take(x, i)

• Inputs:
  • L, a basic list,
  • x, a thing,
  • i, an integer,
  • j, an integer,
  • k, an integer,
• Outputs:
  • L2, a basic list, the list or sequence containing the first i elements of L, (if i positive), or the last i elements of L (if i negative), or, if given the pair j,k, the list or sequence containing the elements of L with indices j through k

Description

i1 : take({a,b,c,d,e,f,g}, 3)

o1 = {a, b, c}

o1 : List

i2 : take({a,b,c,d,e,f,g}, -3)

o2 = {e, f, g}

o2 : List

i3 : take({a,b,c,d,e,f,g}, {1,3})

o3 = {b, c, d}

o3 : List

i4 : take({a,b,c,d,e,f,g}, {2,2})

o4 = {c}

o4 : List

i5 : take({a,b,c,d,e,f,g}, {3,1})

o5 = {}

o5 : List

i6 : take({a,b,c,d,e,f,g}, {4,-1})

o6 = {}

o6 : List

i7 : take("Hello, world!", 5)

o7 = {H, e, l, l, o}

o7 : List

i8 : take("Hello, world!", 20)

o8 = {H, e, l, l, o, ,,  , w, o, r, l, d, !}

o8 : List

See also

• drop -- drop some elements from a list or sequence.
• select -- select from a list, hash table, or string
• position -- the first element of a list satisfying a condition
• positions -- which elements of a list satisfy a condition
• lists and sequences -- a detailed overview of lists and sequences in Macaulay2