Algomatic
Various algorithms and utilities.
 Highly performant: inout arguments and no heap allocations;
 Treeshakeable;
 Thoroughly tested.
Algorithms from this library are used in Paint Bucket color manipulation library, check out its performance.
npm install saveprod algomatic

Checks
isBetween
isEpsClose
isNumeric

Functions
callOrGet

Easing
easeExp
easeLog
easeInQuad
easeOutQuad
easeInOutQuad
easeInCubic
easeOutCubic
easeInOutCubic
easeInQuart
easeOutQuart
easeInOutQuart
easeInQuint
easeOutQuint
easeInOutQuint
Arrays
Utilities
copyOver
range
swap
asc
desc
binarySearch
Searches the specified array for the specified value using the binary search algorithm. The array must be sorted into ascending order according to the natural ordering of its elements prior to making this call. If it is not sorted, the results are undefined.
Returns the index of the searched value, if it is contained in the array; otherwise, (insertion point)  1. The insertion point is defined as the point at which the searched value would be inserted into the array: the index of the first element greater than the searched value, or array length if all elements in the array are less than the specified key. Note that this guarantees that the return value will be ≥ 0 if and only if the searched value is found.
binarySearch([10, 20, 30, 40], 20); // → 1
binarySearch([10, 20, 30, 40], 25); // → 3
sort
Sorts the array inplace using an optional comparator and invokes a callback after a pair of elements was swapped.
sort(
arr, // Mutable array that would be sorted
(i, j) => {
// Called when i and j elements of arr were swapped
// Use this to sort multiple arrays in parallel
},
(a, b) => 0, // Comparator works the same way as in Array.sort
);
sort
uses a nonrecursive Quicksort algorithm. In contrast to
Array.sort
, sort
doesn't convert array elements to strings before comparison and uses comparison operators directly. So numeric arrays
are sorted in natural order with sort(arr)
. You can provide an element comparator to change the sorting order.
sort
is order of magnitude faster than Array.sort
on both small and big arrays. The plot below uses a log scale and
shows the dependency of number of operations per second from the input array length.
Interpolation
lerp
Creates a linear interpolator:
const f = lerp(xs, ys);
const y = f(x);
Here xs
is the array of X coordinates of pivot points in ascending order, and ys
is the array of corresponding Y
coordinates of pivot points.
cspline
Creates a cubic spline interpolator for given pivot points:
const f = cspline(xs, ys);
const y = f(x);
More control over spline caching and computation:
// Preallocate an array of spline components that can be later reused
// to avoid excessive memory allocations
const splines = new Float32Array(xs.length * 3);
createCSplines(xs, ys, xs.length, splines); // → splines
// or
// const splines = createCSplines(xs, ys, xs.length); // → Float32Array
const y = interpolateCSpline(xs, ys, x, xs.length, splines);
csplineMonot
Creates a monotone cubic interpolator for given pivot points:
const f = csplineMonot(xs, ys);
const y = f(x);
Or using more finegrained approach:
const y = interpolateCSplineMonot(xs, ys, x, xs.length, createCSplinesMonot(xs, ys, xs.length));
The plot below shows that cspline
interpolation overshoots pivot points while csplineMonot
provides monotonous
results.
Bitwise
Bitwise operations left
,
right
,
and
,
or
and xor
for unsigned integers that exceed 32bit range:
left(0xAB, 8); // Same as 0xAB << 8
// → 0xAB_00
left(0xAB_CD_EF_AB_CD, 24)
// → 0xAB_CD_EF_AB_CD_00_00_00
right(0xAB_CD, 8); // Same as 0xAB_CD >> 8
// → 0xAB