number-pairs v1.0.3
number-pairs
Javascript utility for dealing with ranges of numbers and/or dates expressed as length-2 arrays.
contains
tests if a range expressed as a pair of numbers contains some other value
contains([2,6],4) // true, 4 is in contained in the range 2-6
contains([2,6],7) // false
A range is considered to contain its lower bound but not its upper:
contains([2,6],2) // true
contains([2,6],5.99) // true
contains([2,6],6) // false
centredOn
Creates a new range of the same size, but centred around a new value (think panning):
centredOn([2,3], 10) // [-9.5, 10.5]
mid
Calculates the midpoint of a pair of numbers
mid(-5, 5) // 0
mid(5, 10) // 7.5
pairExtent
pairExtent(-1, 10) // 11
interpolateBetweenPair
interpolateBetweenPair([5,10], 0.5) // 7.5
interpolateBetweenPair([5,10], 0) // 5
interpolateBetweenPair([5,10], 1) // 10
rangesOverlap
rangesOverlap([1,4],[3,8]) // returns true - these ranges overlap
rangesOverlap([1,4],[5,8]) // returns false - these ranges do notoverlap
overlap
overlap(a,b,c,d)
// same as:
rangesOverlap([a,b], [c,d])
expandPair
Expand a range so that it the returned value is proptionally larger (or smaller) than the given value.
it holds that:
extent( expand( r, n ) ) / extent(r) === n
so, to double the extent of a range:
expand( r, 2 )
to half the extent of a range:
expand( r, 0.5 )
max
Enforces the maximum extent of a range, while keeping the centre point the same (think viewport minimum)
max([a,b], maxExtent)
min
Enforces the minimum extent of a range, while keeping the centre point the same (think viewport minimum)
min([a,b], minExtent)