VisibleList / Function -- apply a function to elements of a list

Synopsis

• Operator: /

• Usage:

  x/f

  f\x

• Inputs:
  • x, a visible list, a list, a sequence, an array, a tally, a set, or a string
  • f, a function, a command, a self initializing type, or a ring map
• Outputs:
  • a visible list, the list, tally, or set obtained by applying f to each element of x; it has the same type as x has

Description

The function apply does the same thing.

The operator / is left associative, which means that w / f / g is interpreted as (w / f) / g. The operator \ is right associative, so g \ f \ w is interpreted as g \ (f \ w). Both operators have parsing precedence lower than that of @@, which means that the previous two expressions are equivalent to w / g @@ f and g @@ f \ w, respectively. See precedence of operators.

i1 : f = x -> x+1

o1 = f

o1 : FunctionClosure

i2 : g = x -> 2*x

o2 = g

o2 : FunctionClosure

i3 : g \ (1 .. 10)

o3 = (2, 4, 6, 8, 10, 12, 14, 16, 18, 20)

o3 : Sequence

i4 : (1 .. 10) / g

o4 = (2, 4, 6, 8, 10, 12, 14, 16, 18, 20)

o4 : Sequence

i5 : f \ g \ (1 .. 10)

o5 = (3, 5, 7, 9, 11, 13, 15, 17, 19, 21)

o5 : Sequence

i6 : f @@ g \ (1 .. 10)

o6 = (3, 5, 7, 9, 11, 13, 15, 17, 19, 21)

o6 : Sequence

i7 : set (1 .. 10)

o7 = set {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

o7 : Set

i8 : g \ oo

o8 = set {16, 18, 2, 20, 4, 6, 8, 10, 12, 14}

o8 : Set

i9 : R = QQ[x];

i10 : f = map(R,R,{x^2})

                   2
o10 = map (R, R, {x })

o10 : RingMap R <-- R

i11 : f \ {x,x^2,x^3,x^4}

        2   4   6   8
o11 = {x , x , x , x }

o11 : List