meows/build/types/math.d.ts

A kittybin of tools.

export declare type fraction = [number, number];
/**
 * A suite of random tools.
 */
export declare class Rand {
    static int: (min?: number, max?: number) => number;
    static real: (min?: number, max?: number) => number;
    /** Gives a weak random boolean. */
    static wBool: () => boolean;
    /**
     * Given natural `n` → returns `n` strong random booleans.
     * @example
     * Rand.bool() ? 'heads' : 'tails'
     * Rand.bool(10).filter(x => x)
     */
    static bool(nat?: number): boolean | boolean[];
}
/** Generate an array of `n` strong random integers. */
export declare const randomInts: (n?: number) => Uint8Array | Int8Array | Int16Array | Int32Array | Uint16Array | Uint32Array | Uint8ClampedArray | Float32Array | Float64Array | DataView;
export declare const sum: (nums: number[]) => number;
export declare const product: (nums: number[]) => number;
/**
 * Finds the difference in magnitude between two numbers.
 * @example
 * diff_abs(10, -3)  // => 13
 * diff_abs(-5, 5)   // => 10
 */
export declare const diff_abs: (a: number, b: number) => number;
/**
 * Finds the delta of unidimensional array of reals.
 * @example
 * diff_nums([0, 0, 1, 3, 6, 10, 15])  // => [0, 1, 2, 3, 4, 5]
 */
export declare const diff_nums: (nums: number[]) => any[];
/**
 * Converts an integer to an array of its digits.
 * @example
 * int_to_digits(123450)  // => [1, 2, 3, 4, 5, 0]
 * int_to_digits(1/0)     // => []
 */
export declare const int_to_digits: (int: number, base?: number) => number[];
/**
 * Randomly signs a signable number. If the value isn't signable, return `NaN`.
 * @example
 * const backoff = (tries) => 2**tries + plus_or_minus(Math.random())
 */
export declare const plus_or_minus: (num: number) => number;
/** Check if strictly equal to `0`. */
export declare const isZero: (num: any) => boolean;
/** Floor division that returns `NaN` for non-number inputs. */
export declare const fdiv: (num: number, div: number) => number;
/**
 * Returns the result of a division operation in the form of an array, with the
 * first item as the whole quotient, and the second item as the remainder.
 *
 * @example
 * divmod(13, 2)    // => [6, 1]
 * divmod(12, 2)    // => [6, 0]
 * divmod(12.5, 2)  // => [6, 0.5]
 */
export declare const divmod: (num: number, div: number) => [number, number];
/**
 * Takes a decimal number and separates its whole part from its fractional part.
 *
 * @example
 * splitDecimal(3)     // => [3, 0]
 * splitDecimal(3.5)   // => [3, 0.5]
 * splitDecimal(0.5)   // => [0, 0.5]
 * splitDecimal(0)     // => [0, 0]
 * splitDecimal(null)  // => [NaN, NaN]
 */
export declare function splitDecimal(real: number): [number, number];
/** Replacement for `Math.floor`. */
export declare const floor: (x: number) => number;
/** Changes a signable number into negative. */
export declare const negative: (num: number) => number;
/** Changes a signable number into positive. */
export declare const positive: (num: number) => number;
/**
 * Flips the sign on a signable number, but excludes `null`.
 * @example
 * flipSign(0)     // => -0
 * flipSign(-0)    // => 0
 * flipSign(1/0)   // => -Infinity
 * flipSign(NaN)   // => NaN
 * flipSign(null)  // => NaN
 */
export declare const flipSign: (num: number) => number;
/**
 * Takes target real number and a maximum denominator for precision and finds
 * the simplest and closest fraction up to that target real in the form of an
 * array: `[numerator, divisor]`.

 * @example
 * realToFraction(0.23, 10)      // => [2, 9]
 * realToFraction(0.31415, 100)  // => [11, 35]
 * realToFraction(NaN, NaN)      // => [NaN, NaN]
 */
export declare function realToFraction(real: number, denMax: number): fraction;
/**
 * Simplifies a fraction by recursively looking for greatest common divisor
 * ("gcd") of the numerator and divisor (denominator). Returns a fraction in the
 * form of an array, with the numerator being the first item, and the divisor
 * being the second.
 *
 * @example
 * simplifyFraction(6/3)  // => [2, 1]
 * simplifyFraction(3/6)  // => [1, 2]
 * simplifyFraction(1/2)  // => [1, 2]
 * simplifyFraction(1/0)  // => [NaN, NaN]
 */
export declare function simplifyFraction(num: number, div: number): fraction;