diff --git a/smop/runtime.py b/smop/runtime.py
index ec70b244..e03651d0 100644
--- a/smop/runtime.py
+++ b/smop/runtime.py
@@ -212,6 +212,12 @@ def size_(a, b=0, nargout=2):
     except IndexError:
         return 1
 
+def strread(s, format="", nargout=1):
+    if format == "":
+        a = [float(x) for x in s.split()]
+        return tuple(a) if nargout > 1 else np.asarray([a])
+    raise ErrorNotImplemented
+
 def sum_(a):
     return asarray(a).sum()
 
diff --git a/smop/tests.py b/smop/tests.py
new file mode 100644
index 00000000..8b530cb4
--- /dev/null
+++ b/smop/tests.py
@@ -0,0 +1,284 @@
+# SMOP compiler runtime support library
+# Copyright 2014 Victor Leikehman
+
+# MIT license
+import numpy as np
+import unittest
+from runtime import *
+
+"""
+Matlab matrices differ from numpy arrays:
+
+o Array indices start with one, not with zero.  Accordingly, the last
+  element of an N-element array is N, not N-1 as in C.
+
+o Matrix elements are ordered column-first, aka "Fortran" order.
+
+o Arrays auto-expand on out-of-bound lhs indexing.
+
+o Array data is not shared by copying or slice indexing. Instead there
+  is copy-on-write.
+
+o There are no zero or one-dimensional arrays. Scalars are
+  two-dimensional rather than zero=dimensional as in numpy.
+
+o Strings are not yet supported.
+"""
+
+class Index(unittest.TestCase):
+    def setUp(self):
+        self.a = matlabarray(arange_(1,4).reshape(2,2,order="F"))
+
+    def test01(self):
+        """
+        One-dimensional LHS indexing of multi-dimensional array,
+        without expansion.  Using scalar index.
+        """
+        self.a[4]=9
+        self.assertTrue(isequal_(self.a, [[1, 3],[2, 9]]))
+
+    def test02(self):
+        """
+        Multi-dimensional LHS indexing, without expansion.
+        """
+        a=matlabarray(zeros_(2,2))
+        a[1,1]=11
+        a[2,2]=22
+        a[1,2]=12
+        a[2,1]=21
+        self.assertTrue(isequal_(a, [[11,12],[21,22]]))
+
+class Indices(unittest.TestCase):
+    """Test matlabarray.compute_indices"""
+    def setUp(self):
+        self.a = matlabarray(arange_(1,20).reshape(4,5,order="F"))
+
+    # one dimension
+    def test01(self):
+        indices = self.a.compute_indices(100)
+        self.assertEqual(indices,(99,))
+
+    def test02(self):
+        indices = self.a.compute_indices(slice(None,None,None))
+        self.assertEqual(indices,(slice(0,20,1),))
+        
+    def test03(self):
+        indices = self.a.compute_indices(slice(0,20,1))
+        self.assertEqual(indices,(slice(0,20,1),))
+
+    # two dimensions
+    def test04(self):
+        indices = self.a.compute_indices((slice(None,None,None),
+                                          slice(None,None,None)))
+        self.assertEqual(indices,(slice(0,4,1),slice(0,5,1)))
+
+    # broadcast
+    #def test05(self):
+    #    indices = self.a.compute_indices(([1,1,1],
+    #                                      slice(None,None,None)))
+    #    
+    #    (array([0, 0, 0]), slice(0, 5, 1))
+        
+
+class Getitem(unittest.TestCase):
+    def setUp(self):
+        self.a = matlabarray(arange_(1,20).reshape(4,5,order="F"))
+    # 2-dim
+    def test01(self):
+        self.assertEqual(self.a[1,1],1)
+
+    def test02(self):
+        self.assertEqual(self.a[4,5],20)
+
+    def test03(self):
+        self.assertTrue(isequal_(self.a[:,:],self.a))
+
+    # 1-dim
+    def test04(self):
+        self.assertTrue(isequal_(self.a[:],arange_(1,20)))
+
+    def test05(self):
+        z = [[1,2,3,4],
+             [1,2,3,4],
+             [1,2,3,4]]
+        a = matlabarray([[1,2,3,4]])
+        self.assertTrue(isequal_(a[[1,1,1],1:4], z))
+        self.assertTrue(isequal_(a[[[1,1,1]],1:4], z))
+        self.assertTrue(isequal_(a[[1,1,1], : ], z))
+            
+class Slice(unittest.TestCase):
+    def setUp(self):
+        self.a = matlabarray(arange_(1,4).reshape(2,2,order="F"))
+
+    def test01(self):
+        self.assertTrue(isequal_(self.a[1:4],[1,2,3,4]))
+        self.assertEqual(self.a[1,1], 1)
+        self.assertEqual(self.a[2,1], 2)
+        self.assertEqual(self.a[1,2], 3)
+        self.assertEqual(self.a[2,2], 4)
+
+    def test02(self):
+        self.a[1,1] = 11
+        self.a[2,1] = 22
+        self.a[1,2] = 33
+        self.a[2,2] = 44
+        self.assertTrue(isequal_(self.a[1:4],[11,22,33,44]))
+
+    def test03(self):
+        self.a[1] = 11
+        self.a[2] = 22
+        self.a[3] = 33
+        self.a[4] = 44
+        self.assertTrue(isequal_(self.a[1:4],[11,22,33,44]))
+
+    def test04(self):
+        #with self.assertRaises(ValueError):
+        self.a[1:4]=[11,22,33,44]
+        self.assertTrue(isequal_(self.a[1:4],[11,22,33,44]))
+
+    def test05(self):
+        self.a[:,:]=[[11,33],[22,44]]
+        self.assertTrue(isequal_(self.a[1:4],[11,22,33,44]))
+
+    def test06(self):
+        self.a[:]=[11,22,33,44]
+        self.assertTrue(isequal_(self.a[1:4],[11,22,33,44]))
+
+    def test07(self):
+        self.a[::3]=[11,44]
+        self.assertTrue(isequal_(self.a[1:4],[11,2,3,44]))
+
+    def test08(self):
+        self.a[1:4:3]=[11,44]
+        self.assertTrue(isequal_(self.a[1:4],[11,2,3,44]))
+
+    @unittest.skip("")
+    def test_007(self):
+        """
+        One-dimensional LHS indexing without expansion, 
+        using list index.
+        """
+        a=zeros_(2,2)
+        a[[1,4]]=1
+        self.assertEqual(str(a), "[[ 1.  0.]\n [ 0.  1.]]")
+
+    @unittest.skip("")
+    def test_008(self):
+        a=zeros_(2,2)
+        a[[4,3,2,1]]=[1,2,3,4]
+        self.assertEqual(str(a), "[[ 1.  2.]\n [ 3.  4.]]")
+
+
+
+    @unittest.skip("")
+    def test_010(self):
+        a=zeros_(2,2)
+        a[2,:]=[1,2]
+        self.assertEqual(str(a), "[[ 0.  0.]\n [ 1.  2.]]")
+
+    @unittest.skip("")
+    def test_011(self):
+        a=zeros_(2,2)
+        a[2,1:2]=[1,2]
+        self.assertEqual(str(a), "[[ 0.  0.]\n [ 1.  2.]]")
+
+    @unittest.skip("")
+    def test_012(self):
+        a=zeros_(2,2)
+        a[2,[1,2]]=[1,2]
+        self.assertEqual(str(a), "[[ 0.  0.]\n [ 1.  2.]]")
+
+    @unittest.skip("")
+    def test_013(self):
+        a=zeros_(2,2)
+        a[:,:]=[[1,2],[3,4]]
+        self.assertEqual(str(a), "[[ 1.  2.]\n [ 3.  4.]]")
+
+    @unittest.skip("")
+    def test_014(self):
+        a=zeros_(2,2)  
+        with self.assertRaises(ValueError):
+            a[:,:]=[1,2,3,4]
+
+class Expand(unittest.TestCase):
+    """
+    Expand on index error  
+    """
+    def setUp(self):
+        self.a = matlabarray(zeros_(1,4))
+
+    def test01(self):
+        self.a[1,5]=1
+        self.assertTrue(isequal_(self.a,
+                              matlabarray([[0,0,0,0,1]])))
+
+    def test02(self):
+        with self.assertRaises(NotImplementedError):
+            self.a[5]=1 # single index
+
+    @unittest.skip("")
+    def test03(self):
+        a=zeros_(1,4) 
+        a[1:10:4]=1
+        "[[ 1.  0.  0.  0.  1.  0.  0.  0.  1.  0.]]"
+
+    def test04(self):
+        self.a[5,5]=1
+        b = matlabarray(
+            [[0,0,0,0,0],
+             [0,0,0,0,0],
+             [0,0,0,0,0],
+             [0,0,0,0,0],
+             [0,0,0,0,1]])
+        self.assertTrue(isequal_(self.a,b))
+
+class Strread(unittest.TestCase):
+    def test01(self):
+        a = strread("0.11 0.22 0.33")
+        self.assertTrue(isequal_(a,[[0.11,0.22,0.33]]))
+
+    def test02(self):
+        a,b,c = strread("0.11 0.22 0.33",nargout=3)
+        self.assertEqual(a,0.11)
+        self.assertEqual(b,0.22)
+        self.assertEqual(c,0.33)
+
+class Core(unittest.TestCase):
+    def setUp(self):
+        self.a = arange_(1,10).reshape(2,5,order="F")
+
+    def test01(self):
+        b = abs_(-self.a)
+        self.assertTrue(isequal_(self.a,b))
+
+    def test02(self):
+        b = ceil_(self.a)
+        self.assertTrue(isequal_(self.a,b))
+
+    def test03(self):
+        b = false_(2,3)
+        self.assertEqual(size_(b), (2,3))
+
+    def test_zeros(self):
+        self.assertEqual(zeros_(), 0.0)
+        self.assertTrue(isequal_(zeros_(2), zeros_(2,2)))
+        self.assertTrue(isequal_(zeros_(2,2), zeros_(2,2)))
+
+        
+#class Copy(unittest.TestCase):
+#    def setUp(self):
+#        self.a = zeros_(1,4)
+#
+#    def test01(self):
+#        b=self.a.copy()
+#        print self.a
+#        print b
+#        self.assertTrue(isequal_(self.a,b))
+#        b[1,1]=123
+#        self.assertTrue(not isequal_(self.a,b))
+#        #c=b.copy()
+#        #c[1,:]=1
+#        #self.assertTrue(not isequal_(b,c))
+
+if __name__ == "__main__":
+    unittest.main()