diff --git a/pyttb/cp_apr.py b/pyttb/cp_apr.py
index fbe1c044..d1eb6e9b 100644
--- a/pyttb/cp_apr.py
+++ b/pyttb/cp_apr.py
@@ -15,7 +15,7 @@ def cp_apr(tensor, rank, algorithm='mu', stoptol=1e-4, stoptime=1e6, maxiters=10
            kappa=0.01, kappatol=1e-10, epsActive=1e-8, mu0=1e-5, precompinds=True, inexact=True,
            lbfgsMem=3):
     """
-    Compute nonnegative CP with alternating Poisson regression.
+    Compute non-negative CP with alternating Poisson regression.
     
     Parameters
     ----------
@@ -376,9 +376,10 @@ def tt_cp_apr_pdnr(tensor, rank, init, stoptol, stoptime, maxiters, maxinneriter
         sparseIx = []
         for n in range(N):
             num_rows = M[n].shape[0]
-            sparseIx.append(np.zeros((num_rows, 1)))
+            row_indices = []
             for jj in range(num_rows):
-                sparseIx[n][jj] = np.where(tensor.subs[:, n] == jj)[0]
+                row_indices.append(np.where(tensor.subs[:, n] == jj)[0])
+            sparseIx.append(row_indices)
 
         if printitn > 0:
             print('done\n')
@@ -426,7 +427,7 @@ def tt_cp_apr_pdnr(tensor, rank, init, stoptol, stoptime, maxiters, maxinneriter
                         M.factor_matrices[n][jj, :] = 0
                         continue
 
-                    x_row = tensor.vals(sparse_indices)
+                    x_row = tensor.vals[sparse_indices]
 
                     # Calculate just the columns of Pi needed for this row.
                     Pi = ttb.tt_calcpi_prowsubprob(tensor, M, rank, n, N, isSparse, sparse_indices)
@@ -683,9 +684,10 @@ def tt_cp_apr_pqnr(tensor, rank, init, stoptol, stoptime, maxiters, maxinneriter
         sparseIx = []
         for n in range(N):
             num_rows = M[n].shape[0]
-            sparseIx.append(np.zeros((num_rows, 1)))
+            row_indices = []
             for jj in range(num_rows):
-                sparseIx[n][jj] = np.where(tensor.subs[:, n] == jj)[0]
+                row_indices.append(np.where(tensor.subs[:, n] == jj)[0])
+            sparseIx.append(row_indices)
 
         if printitn > 0:
             print('done\n')
@@ -726,7 +728,7 @@ def tt_cp_apr_pqnr(tensor, rank, init, stoptol, stoptime, maxiters, maxinneriter
                         M.factor_matrices[n][jj, :] = 0
                         continue
 
-                    x_row = tensor.vals(sparse_indices)
+                    x_row = tensor.vals[sparse_indices]
 
                     # Calculate just the columns of Pi needed for this row.
                     Pi = ttb.tt_calcpi_prowsubprob(tensor, M, rank, n, N, isSparse, sparse_indices)
@@ -1227,7 +1229,7 @@ def tt_loglikelihood_row(isSparse, data_row, model_row, Pi):
     """
     term1 = -np.sum(model_row)
     if isSparse:
-        term2 = np.sum(data_row.transpose() * np.log(model_row.dot(Pi)))
+        term2 = np.sum(data_row.transpose() * np.log(model_row.dot(Pi.transpose())))
     else:
         b_pi = model_row.dot(Pi.transpose())
         term2 = 0
diff --git a/pyttb/sptensor.py b/pyttb/sptensor.py
index 38e586d0..4092753a 100644
--- a/pyttb/sptensor.py
+++ b/pyttb/sptensor.py
@@ -380,7 +380,6 @@ def end(self, k = None):
         Parameters
         ----------
         k: int Dimension for subscript indexing
-        n: int 1 for linear indexing, ndims for subscript
 
         Returns
         -------
@@ -419,11 +418,14 @@ def extract(self, searchsubs):
         invalid = (searchsubs < 0) | (searchsubs >= np.array(self.shape))
         badloc = np.where(np.sum(invalid, axis=1) > 0)
         if badloc[0].size > 0:
-            print('The following subscripts are invalid: \n')
+            error_msg = "The following subscripts are invalid: \n"
             badsubs = searchsubs[badloc, :]
             for i in np.arange(0, badloc[0].size):
-                print('\tsubscript = {}) \n'.format(tt_intvec2str(badsubs[i, :])))
-            assert False, 'Invalid subscripts'
+                error_msg += f"\tsubscript = {tt_intvec2str(badsubs[i, :])} \n"
+            assert False, (
+                f"{error_msg}"
+                'Invalid subscripts'
+            )
 
         # Set the default answer to zero
         a = np.zeros(shape=(p, 1), dtype=self.vals.dtype)
@@ -687,7 +689,7 @@ def mttkrp(self, U, n):
         >>> subs = np.array([[1, 1, 1], [1, 1, 3], [2, 2, 2], [3, 3, 3]])
         >>> vals = np.array([[0.5], [1.5], [2.5], [3.5]])
         >>> shape = (4, 4, 4)
-        >>> sptensorInstance.from_data(subs, vals, shape)
+        >>> sptensorInstance = sptensor.from_data(subs, vals, shape)
         >>> sptensorInstance.mttkrp(np.array([matrix, matrix, matrix]), 0)
         [[0, 0, 0, 0],
         [2, 2, 2, 2],
@@ -962,7 +964,7 @@ def subdims(self, region):
         --------
         >>> subs = np.array([[1, 1, 1], [1, 1, 3], [2, 2, 2], [3, 3, 3]])
         >>> vals = np.array([[0.5], [1.5], [2.5], [3.5]])
-        >>> shape = np.array([4, 4, 4])
+        >>> shape = (4, 4, 4)
         >>> sp = sptensor.from_data(subs,vals,shape)
         >>> region = np.ndarray([1, [1], [1,3]])
         >>> loc = sp.subdims(region)
@@ -1706,7 +1708,7 @@ def __mul__(self, other):
 
         Parameters
         ----------
-        :class:`pyttb.sptensor`, :class:`pyttb.tensor`, float, int
+        other: :class:`pyttb.sptensor`, :class:`pyttb.tensor`, float, int
 
         Returns
         -------
@@ -1748,7 +1750,7 @@ def __rmul__(self, other):
 
         Parameters
         ----------
-        float, int
+        other: float, int
 
         Returns
         -------
diff --git a/pyttb/tenmat.py b/pyttb/tenmat.py
index 9e48f849..c5458794 100644
--- a/pyttb/tenmat.py
+++ b/pyttb/tenmat.py
@@ -13,7 +13,7 @@ class tenmat(object):
 
     """
 
-    def __init__(self, *args):
+    def __init__(self):
         """
         TENSOR Create empty tensor.
         """
@@ -190,10 +190,7 @@ def ndims(self):
         -------
         int
         """
-        if self.shape == (0,):
-            return 0
-        else:
-            return len(self.shape)
+        return len(self.shape)
 
     def norm(self):
         """
diff --git a/pyttb/tensor.py b/pyttb/tensor.py
index dbb39a8d..0cdb49f4 100644
--- a/pyttb/tensor.py
+++ b/pyttb/tensor.py
@@ -103,7 +103,6 @@ def from_tensor_type(cls, source):
             order = np.hstack([source.rindices, source.cindices])
             data = np.reshape(source.data.copy(), np.array(shape)[order], order='F')
             if order.size > 1:
-                # data = ipermute(data, order)
                 data = np.transpose(data, np.argsort(order))
             return cls.from_data(data, shape)
 
@@ -944,7 +943,7 @@ def ttm(self, matrix, dims=None, transpose=False):
 
     def ttt(self, other, selfdims=None, otherdims=None):
         """
-        Tensor mulitplication (tensor times tensor)
+        Tensor multiplication (tensor times tensor)
 
         Parameters
         ----------
@@ -1455,7 +1454,7 @@ def tensor_add(x, y):
 
     def __radd__(self, other):
         """
-        Reverse binary addition (+) for tensors
+        Right binary addition (+) for tensors
 
         Parameters
         ----------
diff --git a/tests/test_cp_apr.py b/tests/test_cp_apr.py
index ed1d28ce..1139e983 100644
--- a/tests/test_cp_apr.py
+++ b/tests/test_cp_apr.py
@@ -125,6 +125,13 @@ def test_cpapr_mu(capsys):
     capsys.readouterr()
     assert output['nTotalIters'] == 2
 
+    # Edge cases
+    # Confirm timeout works
+    non_correct_answer = ktensorInstance*2
+    _ = ttb.cp_apr(tensorInstance, 2, init=non_correct_answer, stoptime=-1)
+    out, _ = capsys.readouterr()
+    assert "time limit exceeded" in out
+
 @pytest.mark.indevelopment
 def test_cpapr_pdnr(capsys):
     # Test simple case
@@ -139,6 +146,23 @@ def test_cpapr_pdnr(capsys):
     capsys.readouterr()
     assert np.isclose(M.full().data, ktensorInstance.full().data, rtol=1e-04).all()
 
+    # Try solve with sptensor
+    sptensorInstance = ttb.sptensor.from_tensor_type(tensorInstance)
+    np.random.seed(123)
+    M, _, _ = ttb.cp_apr(sptensorInstance, 2, algorithm="pdnr")
+    capsys.readouterr()
+    assert np.isclose(M.full().data, ktensorInstance.full().data, rtol=1e-04).all()
+    M, _, _ = ttb.cp_apr(sptensorInstance, 2, algorithm="pdnr", precompinds=False)
+    capsys.readouterr()
+    assert np.isclose(M.full().data, ktensorInstance.full().data, rtol=1e-04).all()
+
+    # Edge cases
+    # Confirm timeout works
+    non_correct_answer = ktensorInstance*2
+    _ = ttb.cp_apr(tensorInstance, 2, init=non_correct_answer, algorithm="pdnr", stoptime=-1)
+    out, _ = capsys.readouterr()
+    assert "time limit exceeded" in out
+
 @pytest.mark.indevelopment
 def test_cpapr_pqnr(capsys):
     # Test simple case
@@ -165,6 +189,22 @@ def test_cpapr_pqnr(capsys):
     capsys.readouterr()
     assert np.isclose(M.full().data, ktensorInstance.full().data, rtol=1e-01).all()
 
+    # Try solve with sptensor
+    sptensorInstance = ttb.sptensor.from_tensor_type(tensorInstance)
+    np.random.seed(123)
+    M, _, _ = ttb.cp_apr(sptensorInstance, 2, algorithm="pqnr")
+    capsys.readouterr()
+    assert np.isclose(M.full().data, ktensorInstance.full().data, rtol=1e-01).all()
+    M, _, _ = ttb.cp_apr(sptensorInstance, 2, algorithm="pqnr", precompinds=False)
+    capsys.readouterr()
+    assert np.isclose(M.full().data, ktensorInstance.full().data, rtol=1e-01).all()
+
+    # Edge cases
+    # Confirm timeout works
+    _ = ttb.cp_apr(tensorInstance, 2, algorithm="pqnr", stoptime=-1)
+    out, _ = capsys.readouterr()
+    assert "time limit exceeded" in out
+
 
 # PDNR tests below
 @pytest.mark.indevelopment
@@ -367,3 +407,22 @@ def test_getSearchDirPqnr():
     search, pred = ttb.getSearchDirPqnr(model_row, phi, 1e-6, delta_model, delta_grad, phi, 1, 5, False)
     # This only verifies that for the right shaped input nothing crashes. Doesn't verify correctness
     assert True
+
+def test_cp_apr_negative_tests():
+    dense_tensor = ttb.tensor.from_data(np.ones((2, 2, 2)))
+    bad_weights = np.array([8.])
+    bad_factors = [np.array([[1.]])] * 3
+    bad_initial_guess_shape = ttb.ktensor.from_data(bad_weights, bad_factors)
+    with pytest.raises(AssertionError):
+        ttb.cp_apr(dense_tensor, init=bad_initial_guess_shape, rank=1)
+    good_weights = np.array([8.] * 3)
+    good_factor = np.array([[1., 1., 1.], [1., 1., 1.]])
+    bad_initial_guess_factors = ttb.ktensor.from_data(good_weights, [-1. * good_factor] * 3)
+    with pytest.raises(AssertionError):
+        ttb.cp_apr(dense_tensor, init=bad_initial_guess_factors, rank=3)
+    bad_initial_guess_weight = ttb.ktensor.from_data(-1. * good_weights, [good_factor] * 3)
+    with pytest.raises(AssertionError):
+        ttb.cp_apr(dense_tensor, init=bad_initial_guess_weight, rank=3)
+
+    with pytest.raises(AssertionError):
+        ttb.cp_apr(dense_tensor, rank=1, algorithm='UNSUPPORTED_ALG')
diff --git a/tests/test_packaging.py b/tests/test_packaging.py
new file mode 100644
index 00000000..3585af32
--- /dev/null
+++ b/tests/test_packaging.py
@@ -0,0 +1,10 @@
+import pyttb as ttb
+import pytest
+
+
+def test_package_smoke():
+    """A few sanity checks to make sure things don't explode"""
+    assert len(ttb.__version__) > 0
+    # Make sure warnings filter doesn't crash
+    ttb.ignore_warnings(False)
+    ttb.ignore_warnings(True)
diff --git a/tests/test_pyttb_utils.py b/tests/test_pyttb_utils.py
index e1982257..b7c52a2b 100644
--- a/tests/test_pyttb_utils.py
+++ b/tests/test_pyttb_utils.py
@@ -3,6 +3,7 @@
 # U.S. Government retains certain rights in this software.
 
 import pyttb as ttb
+import logging
 import numpy as np
 import pytest
 import scipy.sparse as sparse
@@ -172,8 +173,6 @@ def tensor_max(x):
     assert "Tensor 2 is not the same size as the first tensor input" in str(excinfo)
 
 
-
-
 @pytest.mark.indevelopment
 def test_tt_setdiff_rows():
     a = np.array([[4, 6], [1, 9], [2, 6], [2, 6], [99, 0]])
@@ -184,6 +183,10 @@ def test_tt_setdiff_rows():
     b = np.array([[1, 7], [1, 8]])
     assert (ttb.tt_setdiff_rows(a, b) == np.array([0, 1])).all()
 
+    a = np.array([[4, 6], [1, 9]])
+    b = np.array([])
+    assert (ttb.tt_setdiff_rows(a, b) == np.arange(a.shape[0])).all()
+    assert (ttb.tt_setdiff_rows(b, a) == b).all()
 
 @pytest.mark.indevelopment
 def test_tt_intersect_rows():
@@ -191,6 +194,11 @@ def test_tt_intersect_rows():
     b = np.array([[1, 7], [1, 8], [2, 6], [2, 1], [2, 4], [4, 6], [4, 7], [5, 9], [5, 2], [5, 1]])
     assert (ttb.tt_intersect_rows(a, b) == np.array([2, 0])).all()
 
+    a = np.array([[4, 6], [1, 9]])
+    b = np.array([])
+    assert (ttb.tt_intersect_rows(a, b) == b).all()
+    assert (ttb.tt_intersect_rows(a, b) == ttb.tt_intersect_rows(b, a)).all()
+
 
 @pytest.mark.indevelopment
 def test_tt_ismember_rows():
@@ -330,13 +338,13 @@ def test_tt_ind2sub_valid():
     subs = np.array([[0, 0, 0], [1, 1, 1], [3, 3, 3]])
     idx = np.array([0, 21, 63])
     shape = (4, 4, 4)
-    print(f'\nttb.tt_ind2sub(shape, idx): {ttb.tt_ind2sub(shape, idx)}')
+    logging.debug(f'\nttb.tt_ind2sub(shape, idx): {ttb.tt_ind2sub(shape, idx)}')
     assert (ttb.tt_ind2sub(shape, idx) == subs).all()
 
     subs = np.array([[1, 0], [0, 1]])
     idx = np.array([1, 2])
     shape = (2, 2)
-    print(f'\nttb.tt_ind2sub(shape, idx): {ttb.tt_ind2sub(shape, idx)}')
+    logging.debug(f'\nttb.tt_ind2sub(shape, idx): {ttb.tt_ind2sub(shape, idx)}')
     assert (ttb.tt_ind2sub(shape, idx) == subs).all()
 
     empty = np.array([])
diff --git a/tests/test_sptensor.py b/tests/test_sptensor.py
index 1b008e23..d755ee14 100644
--- a/tests/test_sptensor.py
+++ b/tests/test_sptensor.py
@@ -3,6 +3,7 @@
 # U.S. Government retains certain rights in this software.
 
 import pyttb as ttb
+import logging
 import numpy as np
 import pytest
 import scipy.sparse as sparse
@@ -47,9 +48,9 @@ def test_sptensor_initialization_from_tensor_type(sample_sptensor):
     inputData = np.array([[1, 2, 3], [4, 5, 6]])
     tensorInstance = ttb.tensor.from_data(inputData)
     sptensorFromTensor = ttb.sptensor.from_tensor_type(tensorInstance)
-    print(f'inputData = {inputData}')
-    print(f'tensorInstance = {tensorInstance}')
-    print(f'sptensorFromTensor = {sptensorFromTensor}')
+    logging.debug(f'inputData = {inputData}')
+    logging.debug(f'tensorInstance = {tensorInstance}')
+    logging.debug(f'sptensorFromTensor = {sptensorFromTensor}')
     assert (sptensorFromTensor.subs == ttb.tt_ind2sub(inputData.shape, np.arange(0, inputData.size))).all()
     assert (sptensorFromTensor.vals == inputData.reshape((inputData.size, 1), order='F')).all()
     assert (sptensorFromTensor.shape == inputData.shape)
@@ -59,6 +60,11 @@ def test_sptensor_initialization_from_tensor_type(sample_sptensor):
     sptensorFromCOOMatrix = ttb.sptensor.from_tensor_type(sparse.coo_matrix(inputData))
     assert (sptensorFromCOOMatrix.spmatrix() != sparse.coo_matrix(inputData)).nnz == 0
 
+    # Negative Tests
+    with pytest.raises(AssertionError):
+        invalid_tensor_type = []
+        ttb.sptensor.from_tensor_type(invalid_tensor_type)
+
 @pytest.mark.indevelopment
 def test_sptensor_initialization_from_function():
 
@@ -247,6 +253,8 @@ def test_sptensor__getitem__(sample_sptensor):
     ## Case 2 Linear Indexing
     ind = ttb.tt_sub2ind(data['shape'], np.array([[1, 1, 1], [1, 1, 3], [2, 2, 2]]))
     assert (sptensorInstance[ind] == np.array([[0.5], [1.5], [2.5]])).all()
+    list_ind = list(ind)
+    assert (sptensorInstance[list_ind] == np.array([[0.5], [1.5], [2.5]])).all()
     ind2 = ttb.tt_sub2ind(data['shape'], np.array([[1, 1, 1], [1, 1, 3]]))
     assert (sptensorInstance[ind2] == np.array([[0.5], [1.5]])).all()
     with pytest.raises(AssertionError) as excinfo:
@@ -622,15 +630,15 @@ def test_sptensor__eq__(sample_sptensor):
 
     denseTensor = ttb.tensor.from_tensor_type(sptensorInstance)
     eqSptensor = sptensorInstance == denseTensor
-    print(f"\ndenseTensor = {denseTensor}")
-    print(f"\nsptensorInstance = {sptensorInstance}")
-    print(f"\ntype(eqSptensor.subs) = \n{type(eqSptensor.subs)}")
+    logging.debug(f"\ndenseTensor = {denseTensor}")
+    logging.debug(f"\nsptensorInstance = {sptensorInstance}")
+    logging.debug(f"\ntype(eqSptensor.subs) = \n{type(eqSptensor.subs)}")
     for i in range(eqSptensor.subs.shape[0]):
-        print(f"{i}\t{eqSptensor.subs[i,:]}")
-    print(f"\neqSptensor.subs = \n{eqSptensor.subs}")
-    print(f"\neqSptensor.subs.shape[0] = {eqSptensor.subs.shape[0]}")
-    print(f"\nsptensorInstance.shape = {sptensorInstance.shape}")
-    print(f"\nnp.prod(sptensorInstance.shape) = {np.prod(sptensorInstance.shape)}")
+        logging.debug(f"{i}\t{eqSptensor.subs[i,:]}")
+    logging.debug(f"\neqSptensor.subs = \n{eqSptensor.subs}")
+    logging.debug(f"\neqSptensor.subs.shape[0] = {eqSptensor.subs.shape[0]}")
+    logging.debug(f"\nsptensorInstance.shape = {sptensorInstance.shape}")
+    logging.debug(f"\nnp.prod(sptensorInstance.shape) = {np.prod(sptensorInstance.shape)}")
     assert eqSptensor.subs.shape[0] == np.prod(sptensorInstance.shape)
 
     denseTensor = ttb.tensor.from_data(np.ones((5, 5, 5)))
@@ -1371,7 +1379,7 @@ def test_sptensor_ttm(sample_sptensor):
     # This is a multiway multiplication yielding a sparse tensor, yielding a dense tensor relies on tensor.ttm
     matrix = sparse.coo_matrix(np.eye(4))
     list_of_matrices = [matrix, matrix, matrix]
-    assert sptensorInstance.ttm(list_of_matrices, dims=np.array([0, 1, 2])).isequal(sptensorInstance)
+    assert sptensorInstance.ttm(list_of_matrices, dims=[0, 1, 2]).isequal(sptensorInstance)
 
     with pytest.raises(AssertionError) as excinfo:
         sptensorInstance.ttm(sparse.coo_matrix(np.ones((5, 5))), dims=0)
diff --git a/tests/test_tensor.py b/tests/test_tensor.py
index 46d7cf5d..315fa0a7 100644
--- a/tests/test_tensor.py
+++ b/tests/test_tensor.py
@@ -199,7 +199,7 @@ def test_tensor_ndims(sample_tensor_2way, sample_tensor_3way, sample_tensor_4way
     assert ttb.tensor.from_data(np.array([])) == 0
 
 @pytest.mark.indevelopment
-def test_tensor_setitem(sample_tensor_2way):
+def test_tensor__setitem__(sample_tensor_2way):
     (params, tensorInstance) = sample_tensor_2way
 
     # Subtensor assign with constant
@@ -567,6 +567,9 @@ def test_tensor__add__(sample_tensor_2way):
     # Tensor + scalar
     assert ((tensorInstance + 1).data == 1 + (params['data'])).all()
 
+    # scalar + Tensor
+    assert ((1 + tensorInstance).data == 1 + (params['data'])).all()
+
 @pytest.mark.indevelopment
 def test_tensor__sub__(sample_tensor_2way):
     (params, tensorInstance) = sample_tensor_2way
@@ -864,6 +867,14 @@ def test_tensor_collapse(sample_tensor_2way, sample_tensor_3way, sample_tensor_4
     tensorCollapse4Max = tensorInstance4.collapse(np.array([0, 2]), fun=np.max)
     assert (tensorCollapse4Max.data == data4max).all()
 
+    # Empty tensor collapse
+    empty_data = np.array([])
+    empty_tensor = ttb.tensor.from_data(empty_data)
+    assert np.all(empty_tensor.collapse() == empty_data)
+
+    # Empty dims
+    assert tensorInstance2.collapse(empty_data).isequal(tensorInstance2)
+
 @pytest.mark.indevelopment
 def test_tensor_contract(sample_tensor_2way, sample_tensor_3way, sample_tensor_4way):
     (params2, tensorInstance2) = sample_tensor_2way
@@ -1076,6 +1087,17 @@ def test_tensor_ttt(sample_tensor_2way, sample_tensor_3way, sample_tensor_4way):
     assert (TTT1[:,1,1,1,1,1].data == data12).all()
     assert (TTT1[:,2,1,2,3,1].data == data13).all()
 
+    TTT1_with_dims = M31.ttt(M31, selfdims=np.array([0,1,2]), otherdims=np.array([0,1,2]))
+    assert np.allclose(TTT1_with_dims, M31.innerprod(M31))
+
+    # Negative tests
+    with pytest.raises(AssertionError):
+        invalid_tensor_type = []
+        M31.ttt(invalid_tensor_type)
+
+    with pytest.raises(AssertionError):
+        M31.ttt(M31, selfdims=np.array([0, 1, 2]), otherdims=np.array([0, 2, 1]))
+
 
 @pytest.mark.indevelopment
 def test_tensor_ttv(sample_tensor_2way, sample_tensor_3way, sample_tensor_4way):