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colon operator

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    Syntax

    • float[] base : limit
    • float[] base : increment : limit
    Note:

    The colon operator is only available as a parameter for the array initialization function and the index operator (inside a bracket [] notation).

    Parameters

    1. base—float
      Starting value of sequence.
    2. increment—float
      Successively added value to base. Must be positive for an ascending sequence base<=limit or negative for a descending sequence base>=limit. Default is 1.
    3. limit—float
      Maximum/minimum value which is not exceeded.

    Returns

    An array containing a sequence of float values

    [ base, base + increment, base + 2*increment, ... ]

    where the last element does not exceed limit.

    Parameters base, increment and limit are given in a colon-separated notation.

    Note:

    The size of the returned array is limited. It can be configured in the Procedural Runtime preferences (Default: 100000).

    Related

    • Array types operators
    • array initialization function

    Example

    Binary colon operator 

    const a = [2   : 4]      // (3)[2,3,4]
const b = [0.5 : 3]      // (3)[0.5,1.5,2.5]
const c = [4   : 2]      // (0)[]

    Ternary colon operator

    const a = [1 :  0.5 : 3] // (5)[1,1.5,2,2.5,3]
const b = [4 :   -1 : 2] // (3)[4,3,2]
const c = [1 : -0.5 : 2] // (0)[]
const d = [1 : -0.5 : 1] // (1)[1]
const e = [1 :    0 : 1] // (0)[]

    Floating point imprecision

    The computation of sequence values base+i*increment suffers from floating point imprecision. Their exact values might be unexpected. This is not always noticeable when printing values due to an implicit rounding. 

    const a = [0 : 0.15 : 0.5]

Init --> print(a)                        // (4)[0,0.15,0.3,0.45]
         print(a[3] == 0.45)             // false
         print(abs(a[3] - 0.45) < 1e-10) // true

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