input: Write a function to filter out all negative numbers from the given matrix and replace them with 0. The given matrix should be a nested list representing a 2D array. If the input matrix is empty, return an empty matrix.
  import numpy as np
  
  def filter_out_negative(matrix):
    if not matrix:
      return []
    matrix = np.array(matrix)
    matrix[matrix < 0] = 0
    return matrix.tolist()
  
  assert filter_out_negative([[-1, 2, -3], [-4, 5, 6], [-7, 8, 9]]) == [[0, 2, 0], [0, 5, 6], [0, 8, 9]]
  assert filter_out_negative([]) == []
output: def filter_out_negative(matrix):
    if not matrix:
      return []
    matrix = np.array(matrix)
    matrix[matrix < 0] = 0
    return matrix.tolist()