Gamma interpolation function

gamma-interp.js

//N = Math.ceil((x1 - x0) / d + 1))

/**
 * @param {Number} k Gamma.
 * @param {Number} x Interpolation value [0, 1]
 */
const f = (k, x) => (Math.exp(k * Math.max(0, Math.min(1, x)))-1)/(Math.exp(k)-1)

/**
 * @param {Number} k Gamma
 * @param {Number} N Number of steps
 * @param {Number} y0 Start value.
 * @param {Number} y1 End value.
 */
const gi = (k, N, y0, y1) => {
  let dy = (y1-y0)
  return Array.from(Array(N)).map((_, i) => y0 + (y1 - y0) * f(k, i / (N-1)))
}