code: def _nth_point(x, y, n_out):
      """
      Downsampling by selecting every n-th datapoint
  
      Args:
          x (np.ndarray): The x-values of the data.
          y (np.ndarray): The y-values of the data.
          n_out (int): The number of output points.
      Returns:
          np.array: The indexes of the selected datapoints.
      """
      n_samples = len(x)
      return np.arange(
          0, n_samples, max(1, math.ceil(n_samples / n_out))
      )
  
file_path: holoviews/holoviews/operation/downsample.py
imports: import math
  from functools import partial
  import numpy
  import param
  from ..core import NdOverlay, Overlay
  from ..element.chart import Area
  from .resample import ResampleOperation1D
label_desc: Use image node_id 4 for calling a global function with example usage: _nth_point(x, y, n_out) and returns: np