text: from sympy.core import symbols, Lambda
  from sympy.functions import KroneckerDelta
  from sympy.matrices import Matrix
  from sympy.matrices.expressions import FunctionMatrix, MatrixExpr, Identity
  from sympy.testing.pytest import raises
  
  
  def test_funcmatrix_creation():
      i, j, k = symbols('i j k')
      assert FunctionMatrix(2, 2, Lambda((i, j), 0))
      assert FunctionMatrix(0, 0, Lambda((i, j), 0))
  
      raises(ValueError, lambda: FunctionMatrix(-1, 0, Lambda((i, j), 0)))
      raises(ValueError, lambda: FunctionMatrix(2.0, 0, Lambda((i, j), 0)))
      raises(ValueError, lambda: FunctionMatrix(2j, 0, Lambda((i, j), 0)))
      raises(ValueError, lambda: FunctionMatrix(0, -1, Lambda((i, j), 0)))
      raises(ValueError, lambda: FunctionMatrix(0, 2.0, Lambda((i, j), 0)))
      raises(ValueError, lambda: FunctionMatrix(0, 2j, Lambda((i, j), 0)))
  
      raises(ValueError, lambda: FunctionMatrix(2, 2, Lambda(i, 0)))
      raises(ValueError, lambda: FunctionMatrix(2, 2, lambda i, j: 0))
      raises(ValueError, lambda: FunctionMatrix(2, 2, Lambda((i,), 0)))
      raises(ValueError, lambda: FunctionMatrix(2, 2, Lambda((i, j, k), 0)))
      raises(ValueError, lambda: FunctionMatrix(2, 2, i+j))
      assert FunctionMatrix(2, 2, "lambda i, j: 0") == \
          FunctionMatrix(2, 2, Lambda((i, j), 0))
  
      m = FunctionMatrix(2, 2, KroneckerDelta)
      assert m.as_explicit() == Identity(2).as_explicit()
      assert m.args[2] == Lambda((i, j), KroneckerDelta(i, j))
  
      n = symbols('n')
      assert FunctionMatrix(n, n, Lambda((i, j), 0))
      n = symbols('n', integer=False)
      raises(ValueError, lambda: FunctionMatrix(n, n, Lambda((i, j), 0)))
      n = symbols('n', negative=True)
      raises(ValueError, lambda: FunctionMatrix(n, n, Lambda((i, j), 0)))
  
  
  def test_funcmatrix():
      i, j = symbols('i,j')
      X = FunctionMatrix(3, 3, Lambda((i, j), i - j))
      assert X[1, 1] == 0
      assert X[1, 2] == -1
      assert X.shape == (3, 3)
      assert X.rows == X.cols == 3
      assert Matrix(X) == Matrix(3, 3, lambda i, j: i - j)
      assert isinstance(X*X + X, MatrixExpr)
  
  
  def test_replace_issue():
      X = FunctionMatrix(3, 3, KroneckerDelta)
      assert X.replace(lambda x: True, lambda x: x) == X
  