code: def matrix_vector(m, v):
      """Multiply (3,3)-matrix and Vector3D."""
      x = m[0, 0] * v.x + m[0, 1] * v.y + m[0, 2] * v.z
      y = m[1, 0] * v.x + m[1, 1] * v.y + m[1, 2] * v.z
      z = m[2, 0] * v.x + m[2, 1] * v.y + m[2, 2] * v.z
      return Vector3D(x, y, z)
  
imports: from collections import namedtuple
  import dask.array
  import numba
  import numpy
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 39 for calling a global function with example usage: matrix_vector(m, v) and returns: Vector3D