code: def generate_base_anchors(
      stride=16,
      sizes=(32, 64, 128, 256, 512),
      aspect_ratios=(0.5, 1, 2),
  ):
      """Generates a matrix of anchor boxes in (x1, y1, x2, y2) format. Anchors
      are centered on stride / 2, have (approximate) sqrt areas of the specified
      sizes, and aspect ratios as given.
      """
      return _generate_base_anchors(
          stride,
          np.array(sizes, dtype=np.float) / stride,
          np.array(aspect_ratios, dtype=np.float),
      )
  
file_path: gluon-cv/gluoncv/model_zoo/rcnn/rpn/anchor.py
imports: from __future__ import absolute_import
  import numpy
  from mxnet import gluon
label_desc: Use image node_id 1 for calling a global function with example usage: generate_base_anchors(stride, sizes, aspect_ratios) and returns: _generate_base_anchors