How to use the sparse.BlockIndex function in sparse

def test_to_int(self):
        locs = [0, 10]
        lengths = [4, 6]
        exp_inds = [0, 1, 2, 3, 10, 11, 12, 13, 14, 15]

        block = BlockIndex(20, locs, lengths)
        dense = block.to_int()

        assert_equal(dense.indices, exp_inds)

def _check_case(xloc, xlen, yloc, ylen, eloc, elen):
            xindex = BlockIndex(TEST_LENGTH, xloc, xlen)
            yindex = BlockIndex(TEST_LENGTH, yloc, ylen)
            result = xindex.intersect(yindex)

            self.assert_(isinstance(result, BlockIndex))

            assert_equal(result.blocs, eloc)
            assert_equal(result.blengths, elen)

def test_check_integrity(self):
        locs = []
        lengths = []

        # 0-length OK
        index = BlockIndex(0, locs, lengths)

        # also OK even though empty
        index = BlockIndex(1, locs, lengths)

        # block extend beyond end
        self.assertRaises(Exception, BlockIndex, 10, [5], [10])

        # block overlap
        self.assertRaises(Exception, BlockIndex, 10, [2, 5], [5, 3])

def _check_case(xloc, xlen, yloc, ylen, eloc, elen):
            xindex = BlockIndex(TEST_LENGTH, xloc, xlen).to_int()
            yindex = BlockIndex(TEST_LENGTH, yloc, ylen).to_int()

            expected = BlockIndex(TEST_LENGTH, eloc, elen).to_int()

            result = xindex.intersect(yindex)
            self.assert_(isinstance(result, IntIndex))

            assert_equal(result.indices, expected.indices)

def _check_case(xloc, xlen, yloc, ylen, eloc, elen):
            xindex = BlockIndex(TEST_LENGTH, xloc, xlen).to_int()
            yindex = BlockIndex(TEST_LENGTH, yloc, ylen).to_int()

            expected = BlockIndex(TEST_LENGTH, eloc, elen).to_int()

            result = xindex.intersect(yindex)
            self.assert_(isinstance(result, IntIndex))

            assert_equal(result.indices, expected.indices)

def _check_case(xloc, xlen, yloc, ylen):
            xindex = BlockIndex(TEST_LENGTH, xloc, xlen)
            yindex = BlockIndex(TEST_LENGTH, yloc, ylen)

            xdindex = xindex.to_int()
            ydindex = yindex.to_int()

            xvals = np.arange(xindex.npoints) * 10 + 1
            yvals = np.arange(yindex.npoints) * 100 + 1
            x = SparseVector(xvals, xindex)
            y = SparseVector(yvals, yindex)
            xd = SparseVector(xvals, xdindex)
            yd = SparseVector(yvals, ydindex)

            result_block = op(x, y)
            result_dense = op(xd, yd)

            assert_equal(result_block.values, result_dense.values)

def _check_case(xloc, xlen, yloc, ylen, eloc, elen):
            xindex = BlockIndex(TEST_LENGTH, xloc, xlen)
            yindex = BlockIndex(TEST_LENGTH, yloc, ylen)
            result = xindex.intersect(yindex)

            self.assert_(isinstance(result, BlockIndex))

            assert_equal(result.blocs, eloc)
            assert_equal(result.blengths, elen)

def _check_case(xloc, xlen, yloc, ylen, eloc, elen):
            xindex = BlockIndex(TEST_LENGTH, xloc, xlen)
            yindex = BlockIndex(TEST_LENGTH, yloc, ylen)
            result = xindex.intersect(yindex)

            self.assert_(isinstance(result, BlockIndex))

            assert_equal(result.blocs, eloc)
            assert_equal(result.blengths, elen)