Method create

src/Interpolation.js:36–89

(config: InterpolationConfigType)

 */
class Interpolation {
  static create(config: InterpolationConfigType): (input: number) => number | string {

    if (config.outputRange && typeof config.outputRange[0] === 'string') {
      return createInterpolationFromStringOutputRange(config);
    }

    var outputRange: Array<number> = (config.outputRange: any);
    checkInfiniteRange('outputRange', outputRange);

    var inputRange = config.inputRange;
    checkInfiniteRange('inputRange', inputRange);
    checkValidInputRange(inputRange);

    invariant(
      inputRange.length === outputRange.length,
      'inputRange (' + inputRange.length + ') and outputRange (' +
      outputRange.length + ') must have the same length'
    );

    var easing = config.easing || linear;

    var extrapolateLeft: ExtrapolateType = 'extend';
    if (config.extrapolateLeft !== undefined) {
      extrapolateLeft = config.extrapolateLeft;
    } else if (config.extrapolate !== undefined) {
      extrapolateLeft = config.extrapolate;
    }

    var extrapolateRight: ExtrapolateType = 'extend';
    if (config.extrapolateRight !== undefined) {
      extrapolateRight = config.extrapolateRight;
    } else if (config.extrapolate !== undefined) {
      extrapolateRight = config.extrapolate;
    }

    return (input) => {
      invariant(
        typeof input === 'number',
        'Cannot interpolation an input which is not a number'
      );

      var range = findRange(input, inputRange);
      return interpolate(
        input,
        inputRange[range],
        inputRange[range + 1],
        outputRange[range],
        outputRange[range + 1],
        easing,
        extrapolateLeft,
        extrapolateRight,
      );
    };
  }
}

function interpolate(