docs: function evaluateLinear (pointsToEvaluate, functionValuesX, functionValuesY) {
    var results = []
    pointsToEvaluate = help.makeItArrayIfItsNot(pointsToEvaluate)
    pointsToEvaluate.forEach(function (point) {
      var index = help.findIntervalLeftBorderIndex(point, functionValuesX)
      if (index == functionValuesX.length - 1)
        index--
      results.push(linearInterpolation(point, functionValuesX[index], functionValuesY[index]
        , functionValuesX[index + 1], functionValuesY[index + 1]))
    })
    return results
  }