def FindOrderNums(orders, wavelengths):
    """
      Given a list of xypoint orders and
      another list of wavelengths, this
      finds the order numbers with the
      requested wavelengths
    """
    nums = []
    for wave in wavelengths:
        for i, order in enumerate(orders):
            if order.x[0] < wave and order.x[-1] > wave:
                nums.append(i)
                break
    return nums