Reverse

new to Analytica 5.0

Reverse( x, I, posFirst, posLast)

Reverses the items in array «x» along index «I». The result is still indexed by «I».

Use the optional «posFirst» and «posLast» to reverse the order of a sub-sequence along «I».

Examples

Suppose

Index J := 1..6

Variable a := J^2

Reverse(a,J) → Array(J, [ 36, 25, 16, 9, 4, 1 ])

Reverse(a,J,posFirst:3) → Array(J, [ 1,4, 36, 25, 16, 9 ])

Reverse(a,J,posLast:4) → Array(J, [ 16, 9, 4, 1, 25, 36 ])

Reverse(a,J,posFirst:3, posLast:5) → Array(J, [ 1, 4, 25, 16, 9, 36 ])

Notes

• Reverse(x,I) is equivalent to x[@I=size(I)+1-@I].

• Reverse does not reverse the characters in a text value, since a text value is not an array. See TextReverse for a User-Defined Function that does this.

See also

• Subscript-Slice Operator, Slice()
• Sort, Sequence