input: Write a function to filter out all negative numbers from the given matrix. Each element in the matrix that is negative should be replaced with 0. The function should return the modified matrix.
  import numpy as np
  
  def filter_out_negative(matrix):
    # Convert matrix to numpy array
    matrix = np.array(matrix)
    # Find all negative numbers and set them to 0
    matrix[matrix < 0] = 0
    return matrix
  
  assert np.array_equal(filter_out_negative([[-1, 2, -3], [-4, 5, 6], [-7, 8, 9]]), np.array([[0, 2, 0], [0, 5, 6], [0, 8, 9]]))
  assert np.array_equal(filter_out_negative([[1, -2, 3], [4, -5, -6], [7, 8, -9]]), np.array([[1, 0, 3], [4, 0, 0], [7, 8, 0]]))
  assert np.array_equal(filter_out_negative([[0, -1, -2], [-3, -4, -5], [-6, -7, -8]]), np.array([[0, 0, 0], [0, 0, 0], [0, 0, 0]]))
  assert np.array_equal(filter_out_negative([[]]), np.array([[]]))
  assert np.array_equal(filter_out_negative([]), np.array([]))
output: def filter_out_negative(matrix):
    matrix = np.array(matrix)
    matrix[matrix < 0] = 0
    return matrix