def iterchunks(self, blen=None, start=None, stop=None):
"""Return chunks of size `blen` (in leading dimension).
Parameters
----------
blen : int
The length, in rows, of the buffers that are returned.
start : int
Where the iterator starts. The default is to start at the
beginning.
stop : int
Where the iterator stops. The default is to stop at the end.
Returns
-------
out : iterable
This iterable returns buffers as NumPy arays of
homogeneous or structured types, depending on whether
`self.original` is a barray or a btable object.
See Also
--------
wherechunks
"""
# Return the iterable
return blz.iterblocks(self.blzarr, blen, start, stop)
def test03(self):
"""Testing `iterchunks` method with all parameters set"""
N, blen = int(1e4), 100
a = blz.fromiter(xrange(N), dtype=np.float64, count=N)
l, s = 0, 0
for block in blz.iterblocks(a, blen, blen-1, 3*blen+2):
l += len(block)
s += block.sum()
self.assert_(l == 2*blen + 3)
self.assert_(s == np.arange(blen-1, 3*blen+2).sum())
def test02(self):
"""Testing `iterchunks` method with no stop"""
N, blen = int(1e4), 100
a = blz.fromiter(xrange(N), dtype=np.float64, count=N)
l, s = 0, 0
for block in blz.iterblocks(a, blen, blen-1):
l += len(block)
s += block.sum()
self.assert_(l == (N - (blen - 1)))
self.assert_(s == np.arange(blen-1, N).sum())
def test01(self):
"""Testing `iterchunks` method with no start, no stop"""
N, blen = int(1e4), 100
a = blz.fromiter(xrange(N), dtype=np.float64, count=N)
l, s = 0, 0
for block in blz.iterblocks(a, blen):
self.assert_(len(block) == blen)
l += len(block)
s += block.sum()
self.assert_(l == N)
def test00(self):
"""Testing `iterchunks` method with no blen, no start, no stop"""
N = int(1e4)
a = blz.fromiter(xrange(N), dtype=np.float64, count=N)
l, s = 0, 0
for block in blz.iterblocks(a):
l += len(block)
s += block.sum()
self.assert_(l == N)
self.assert_(s == (N - 1) * (N / 2)) # as per Gauss summation formula
def test03(self):
"""Testing `iterchunks` method with all parameters set"""
N, blen = int(1e4), 100
ra = np.fromiter(((i, i*2., i*3) for i in xrange(N)), dtype='i4,f8,i8')
t = blz.btable(ra)
l, s = 0, 0
for block in blz.iterblocks(t, blen, blen-1, 3*blen+2):
l += len(block)
s += block['f2'].sum()
self.assert_(l == 2*blen + 3)
self.assert_(s == (np.arange(blen-1, 3*blen+2)*3).sum())
def test02(self):
"""Testing `iterchunks` method with no stop"""
N, blen = int(1e4), 100
ra = np.fromiter(((i, i*2., i*3) for i in xrange(N)), dtype='i4,f8,i8')
t = blz.btable(ra)
l, s = 0, 0.
for block in blz.iterblocks(t, blen, blen-1):
l += len(block)
s += block['f1'].sum()
self.assert_(l == (N - (blen - 1)))
self.assert_(s == (np.arange(blen-1, N, dtype='f8')*2).sum())
def test00(self):
"""Testing `iterchunks` method with no blen, no start, no stop"""
N = int(1e4)
ra = np.fromiter(((i, i*2., i*3) for i in xrange(N)), dtype='i4,f8,i8')
t = blz.btable(ra)
l, s = 0, 0
for block in blz.iterblocks(t):
l += len(block)
s += block['f0'].sum()
self.assert_(l == N)
self.assert_(s == (N - 1) * (N / 2)) # as per Gauss summation formula
