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ORPA-pyOpenRPA/Resources/WPy64-3720/python-3.7.2.amd64/Lib/site-packages/dask/array/tests/test_rechunk.py

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23 KiB

from itertools import product
import warnings
import pytest
np = pytest.importorskip('numpy')
import dask
from dask.utils import funcname
from dask.array.utils import assert_eq
from dask.array.rechunk import intersect_chunks, rechunk, normalize_chunks
from dask.array.rechunk import cumdims_label, _breakpoints, _intersect_1d, _old_to_new
from dask.array.rechunk import plan_rechunk, divide_to_width, merge_to_number
import dask.array as da
def test_rechunk_internals_1():
""" Test the cumdims_label and _breakpoints and
_intersect_1d internal funcs to rechunk."""
new = cumdims_label(((1,1,2),(1,5,1)),'n')
old = cumdims_label(((4, ),(1,) * 5),'o')
breaks = tuple(_breakpoints(o, n) for o, n in zip(old, new))
answer = (('o', 0), ('n', 0), ('n', 1), ('n', 2), ('o', 4), ('n', 4))
assert breaks[0] == answer
answer2 = (('o', 0), ('n', 0), ('o', 1), ('n', 1), ('o', 2),
('o', 3), ('o', 4), ('o', 5), ('n', 6), ('n', 7))
assert breaks[1] == answer2
i1d = [_intersect_1d(b) for b in breaks]
answer3 = [[(0, slice(0, 1))],
[(0, slice(1, 2))],
[(0, slice(2, 4))]]
assert i1d[0] == answer3
answer4 = [[(0, slice(0, 1))],
[(1, slice(0, 1)),
(2, slice(0, 1)),
(3, slice(0, 1)),
(4, slice(0, 1)),
(5, slice(0, 1))],
[(5, slice(1, 2))]]
assert i1d[1] == answer4
def test_intersect_1():
""" Convert 1 D chunks"""
old = ((10, 10, 10, 10, 10), )
new = ((25, 5, 20), )
answer = [(((0, slice(0, 10)), ),
((1, slice(0, 10)), ),
((2, slice(0, 5)), )),
(((2, slice(5, 10)), ), ),
(((3, slice(0, 10)), ), ((4, slice(0, 10)), ))
]
cross = list(intersect_chunks(old_chunks=old, new_chunks=new))
assert answer == cross
def test_intersect_2():
""" Convert 1 D chunks"""
old = ((20, 20, 20, 20, 20), )
new = ((58, 4, 20, 18),)
answer = [(((0, slice(0, 20)), ),
((1, slice(0, 20)), ),
((2, slice(0, 18)), )),
(((2, slice(18, 20)), ), ((3, slice(0, 2)), )),
(((3, slice(2, 20)), ), ((4, slice(0, 2)), )),
(((4, slice(2, 20)), ), )
]
cross = list(intersect_chunks(old_chunks=old, new_chunks=new))
assert answer == cross
def test_rechunk_1d():
"""Try rechunking a random 1d matrix"""
a = np.random.uniform(0, 1, 30)
x = da.from_array(a, chunks=((10, ) * 3, ))
new = ((5, ) * 6,)
x2 = rechunk(x, chunks=new)
assert x2.chunks == new
assert np.all(x2.compute() == a)
def test_rechunk_2d():
"""Try rechunking a random 2d matrix"""
a = np.random.uniform(0, 1, 300).reshape((10, 30))
x = da.from_array(a, chunks=((1, 2, 3, 4), (5, ) * 6))
new = ((5, 5), (15, ) * 2)
x2 = rechunk(x, chunks=new)
assert x2.chunks == new
assert np.all(x2.compute() == a)
def test_rechunk_4d():
"""Try rechunking a random 4d matrix"""
old = ((5, 5), ) * 4
a = np.random.uniform(0, 1, 10000).reshape((10, ) * 4)
x = da.from_array(a, chunks=old)
new = ((10, ), ) * 4
x2 = rechunk(x, chunks=new)
assert x2.chunks == new
assert np.all(x2.compute() == a)
def test_rechunk_expand():
a = np.random.uniform(0, 1, 100).reshape((10, 10))
x = da.from_array(a, chunks=(5, 5))
y = x.rechunk(chunks=((3, 3, 3, 1), (3, 3, 3, 1)))
assert np.all(y.compute() == a)
def test_rechunk_expand2():
(a, b) = (3, 2)
orig = np.random.uniform(0, 1, a ** b).reshape((a,) * b)
for off, off2 in product(range(1, a - 1), range(1, a - 1)):
old = ((a - off, off), ) * b
x = da.from_array(orig, chunks=old)
new = ((a - off2, off2), ) * b
assert np.all(x.rechunk(chunks=new).compute() == orig)
if a - off - off2 > 0:
new = ((off, a - off2 - off, off2), ) * b
y = x.rechunk(chunks=new).compute()
assert np.all(y == orig)
def test_rechunk_method():
""" Test rechunking can be done as a method of dask array."""
old = ((5, 2, 3), ) * 4
new = ((3, 3, 3, 1), ) * 4
a = np.random.uniform(0, 1, 10000).reshape((10, ) * 4)
x = da.from_array(a, chunks=old)
x2 = x.rechunk(chunks=new)
assert x2.chunks == new
assert np.all(x2.compute() == a)
def test_rechunk_blockshape():
""" Test that blockshape can be used."""
new_shape, new_chunks = (10, 10), (4, 3)
new_blockdims = normalize_chunks(new_chunks, new_shape)
old_chunks = ((4, 4, 2), (3, 3, 3, 1))
a = np.random.uniform(0,1,100).reshape((10, 10))
x = da.from_array(a, chunks=old_chunks)
check1 = rechunk(x, chunks=new_chunks)
assert check1.chunks == new_blockdims
assert np.all(check1.compute() == a)
def test_dtype():
x = da.ones(5, chunks=(2,))
assert x.rechunk(chunks=(1,)).dtype == x.dtype
def test_rechunk_with_dict():
x = da.ones((24, 24), chunks=(4, 8))
y = x.rechunk(chunks={0: 12})
assert y.chunks == ((12, 12), (8, 8, 8))
x = da.ones((24, 24), chunks=(4, 8))
y = x.rechunk(chunks={0: (12, 12)})
assert y.chunks == ((12, 12), (8, 8, 8))
x = da.ones((24, 24), chunks=(4, 8))
y = x.rechunk(chunks={0: -1})
assert y.chunks == ((24,), (8, 8, 8))
def test_rechunk_with_empty_input():
x = da.ones((24, 24), chunks=(4, 8))
assert x.rechunk(chunks={}).chunks == x.chunks
pytest.raises(ValueError, lambda: x.rechunk(chunks=()))
def test_rechunk_with_null_dimensions():
x = da.from_array(np.ones((24, 24)), chunks=(4, 8))
assert (x.rechunk(chunks=(None, 4)).chunks ==
da.ones((24, 24), chunks=(4, 4)).chunks)
def test_rechunk_with_integer():
x = da.from_array(np.arange(5), chunks=4)
y = x.rechunk(3)
assert y.chunks == ((3, 2),)
assert (x.compute() == y.compute()).all()
def test_rechunk_0d():
a = np.array(42)
x = da.from_array(a, chunks=())
y = x.rechunk(())
assert y.chunks == ()
assert y.compute() == a
def test_rechunk_empty():
x = da.ones((0, 10), chunks=(5, 5))
y = x.rechunk((2, 2))
assert y.chunks == ((0,), (2,) * 5)
assert_eq(x, y)
def test_rechunk_same():
x = da.ones((24, 24), chunks=(4, 8))
y = x.rechunk(x.chunks)
assert x is y
def test_rechunk_with_zero_placeholders():
x = da.ones((24, 24), chunks=((12, 12), (24, 0)))
y = da.ones((24, 24), chunks=((12, 12), (12, 12)))
y = y.rechunk(((12, 12), (24, 0)))
assert x.chunks == y.chunks
def test_rechunk_minus_one():
x = da.ones((24, 24), chunks=(4, 8))
y = x.rechunk((-1, 8))
assert y.chunks == ((24,), (8, 8, 8))
assert_eq(x, y)
def test_rechunk_intermediates():
x = da.random.normal(10, 0.1, (10, 10), chunks=(10, 1))
y = x.rechunk((1, 10))
assert len(y.dask) > 30
def test_divide_to_width():
chunks = divide_to_width((8, 9, 10), 10)
assert chunks == (8, 9, 10)
chunks = divide_to_width((8, 2, 9, 10, 11, 12), 4)
# Note how 9 gives (3, 3, 3), not (4, 4, 1) or whatever
assert chunks == (4, 4,
2,
3, 3, 3,
3, 3, 4,
3, 4, 4,
4, 4, 4,
)
def test_merge_to_number():
chunks = merge_to_number((10,) * 4, 5)
assert chunks == (10, 10, 10, 10)
chunks = merge_to_number((10,) * 4, 4)
assert chunks == (10, 10, 10, 10)
chunks = merge_to_number((10,) * 4, 3)
assert chunks == (20, 10, 10)
chunks = merge_to_number((10,) * 4, 2)
assert chunks == (20, 20)
chunks = merge_to_number((10,) * 4, 1)
assert chunks == (40,)
chunks = merge_to_number((10,) * 10, 2)
assert chunks == (50,) * 2
chunks = merge_to_number((10,) * 10, 3)
assert chunks == (40, 30, 30)
chunks = merge_to_number((5, 1, 1, 15, 10), 4)
assert chunks == (5, 2, 15, 10)
chunks = merge_to_number((5, 1, 1, 15, 10), 3)
assert chunks == (7, 15, 10)
chunks = merge_to_number((5, 1, 1, 15, 10), 2)
assert chunks == (22, 10)
chunks = merge_to_number((5, 1, 1, 15, 10), 1)
assert chunks == (32,)
chunks = merge_to_number((1, 1, 1, 1, 3, 1, 1), 6)
assert chunks == (2, 1, 1, 3, 1, 1)
chunks = merge_to_number((1, 1, 1, 1, 3, 1, 1), 5)
assert chunks == (2, 2, 3, 1, 1)
chunks = merge_to_number((1, 1, 1, 1, 3, 1, 1), 4)
assert chunks == (2, 2, 3, 2)
chunks = merge_to_number((1, 1, 1, 1, 3, 1, 1), 3)
assert chunks == (4, 3, 2)
chunks = merge_to_number((1, 1, 1, 1, 3, 1, 1), 2)
assert chunks == (4, 5)
chunks = merge_to_number((1, 1, 1, 1, 3, 1, 1), 1)
assert chunks == (9,)
def _plan(old_chunks, new_chunks, itemsize=1, block_size_limit=1e7):
return plan_rechunk(old_chunks, new_chunks,
itemsize=itemsize,
block_size_limit=block_size_limit)
def _assert_steps(steps, expected):
assert len(steps) == len(expected)
assert steps == expected
def test_plan_rechunk():
c = ((20,) * 2) # coarse
f = ((2,) * 20) # fine
nc = ((float('nan'),) * 2) # nan-coarse
nf = ((float('nan'),) * 20) # nan-fine
# Trivial cases
steps = _plan((), ())
_assert_steps(steps, [()])
steps = _plan((c, ()), (f, ()))
_assert_steps(steps, [(f, ())])
# No intermediate required
steps = _plan((c,), (f,))
_assert_steps(steps, [(f,)])
steps = _plan((f,), (c,))
_assert_steps(steps, [(c,)])
steps = _plan((c, c), (f, f))
_assert_steps(steps, [(f, f)])
steps = _plan((f, f), (c, c))
_assert_steps(steps, [(c, c)])
steps = _plan((f, c), (c, c))
_assert_steps(steps, [(c, c)])
# An intermediate is used to reduce graph size
steps = _plan((f, c), (c, f))
_assert_steps(steps, [(c, c), (c, f)])
steps = _plan((c + c, c + f), (f + f, c + c))
_assert_steps(steps, [(c + c, c + c), (f + f, c + c)])
# Same, with unknown dim
steps = _plan((nc + nf, c + c, c + f), (nc + nf, f + f, c + c))
_assert_steps(steps, steps)
# Just at the memory limit => an intermediate is used
steps = _plan((f, c), (c, f), block_size_limit=400)
_assert_steps(steps, [(c, c), (c, f)])
# Hitting the memory limit => partial merge
m = ((10,) * 4) # mid
steps = _plan((f, c), (c, f), block_size_limit=399)
_assert_steps(steps, [(m, c), (c, f)])
steps2 = _plan((f, c), (c, f), block_size_limit=3999, itemsize=10)
_assert_steps(steps2, steps)
# Larger problem size => more intermediates
c = ((1000,) * 2) # coarse
f = ((2,) * 1000) # fine
steps = _plan((f, c), (c, f), block_size_limit=99999)
assert len(steps) == 3
assert steps[-1] == (c, f)
for i in range(len(steps) - 1):
prev = steps[i]
succ = steps[i + 1]
# Merging on the first dim, splitting on the second dim
assert len(succ[0]) <= len(prev[0]) / 2.0
assert len(succ[1]) >= len(prev[1]) * 2.0
def test_plan_rechunk_5d():
# 5d problem
c = ((10,) * 1) # coarse
f = ((1,) * 10) # fine
steps = _plan((c, c, c, c, c), (f, f, f, f, f))
_assert_steps(steps, [(f, f, f, f, f)])
steps = _plan((f, f, f, f, c), (c, c, c, f, f))
_assert_steps(steps, [(c, c, c, f, c), (c, c, c, f, f)])
# Only 1 dim can be merged at first
steps = _plan((c, c, f, f, c), (c, c, c, f, f), block_size_limit=2e4)
_assert_steps(steps, [(c, c, c, f, c), (c, c, c, f, f)])
def test_plan_rechunk_heterogenous():
c = ((10,) * 1) # coarse
f = ((1,) * 10) # fine
cf = c + f
cc = c + c
ff = f + f
fc = f + c
# No intermediate required
steps = _plan((cc, cf), (ff, ff))
_assert_steps(steps, [(ff, ff)])
steps = _plan((cf, fc), (ff, cf))
_assert_steps(steps, [(ff, cf)])
# An intermediate is used to reduce graph size
steps = _plan((cc, cf), (ff, cc))
_assert_steps(steps, [(cc, cc), (ff, cc)])
steps = _plan((cc, cf, cc), (ff, cc, cf))
_assert_steps(steps, [(cc, cc, cc), (ff, cc, cf)])
# Imposing a memory limit => the first intermediate is constrained:
# * cc -> ff would increase the graph size: no
# * ff -> cf would increase the block size too much: no
# * cf -> cc fits the bill (graph size /= 10, block size neutral)
# * cf -> fc also fits the bill (graph size and block size neutral)
steps = _plan((cc, ff, cf), (ff, cf, cc), block_size_limit=100)
_assert_steps(steps, [(cc, ff, cc), (ff, cf, cc)])
def test_plan_rechunk_asymmetric():
a = ((1,) * 1000, (80000000,))
b = ((1000,), (80000,) * 1000)
steps = plan_rechunk(a, b, itemsize=8)
assert len(steps) > 1
x = da.ones((1000, 80000000), chunks=(1, 80000000))
y = x.rechunk((1000, x.shape[1] // 1000))
assert len(y.dask) < 100000
def test_rechunk_warning():
N = 20
x = da.random.normal(size=(N, N, 100), chunks=(1, N, 100))
with warnings.catch_warnings(record=True) as w:
x = x.rechunk((N, 1, 100))
assert not w
@pytest.mark.parametrize('shape,chunks', [[(4,), (2,)],
[(4, 4), (2, 2)],
[(4, 4), (4, 2)]])
def test_dont_concatenate_single_chunks(shape, chunks):
x = da.ones(shape, chunks=shape)
y = x.rechunk(chunks)
dsk = dict(y.dask)
assert not any(funcname(task[0]).startswith('concat')
for task in dsk.values()
if dask.istask(task))
def test_intersect_nan():
old_chunks = ((float('nan'), float('nan')), (8,))
new_chunks = ((float('nan'), float('nan')), (4, 4))
result = list(intersect_chunks(old_chunks, new_chunks))
expected = [
(((0, slice(0, None, None)), (0, slice(0, 4, None))),),
(((0, slice(0, None, None)), (0, slice(4, 8, None))),),
(((1, slice(0, None, None)), (0, slice(0, 4, None))),),
(((1, slice(0, None, None)), (0, slice(4, 8, None))),)
]
assert result == expected
def test_intersect_nan_single():
old_chunks = ((float('nan'),), (10,))
new_chunks = ((float('nan'),), (5, 5))
result = list(intersect_chunks(old_chunks, new_chunks))
expected = [(((0, slice(0, None, None)), (0, slice(0, 5, None))),),
(((0, slice(0, None, None)), (0, slice(5, 10, None))),)]
assert result == expected
def test_intersect_nan_long():
old_chunks = (tuple([float('nan')] * 4), (10,))
new_chunks = (tuple([float('nan')] * 4), (5, 5))
result = list(intersect_chunks(old_chunks, new_chunks))
expected = [
(((0, slice(0, None, None)), (0, slice(0, 5, None))),),
(((0, slice(0, None, None)), (0, slice(5, 10, None))),),
(((1, slice(0, None, None)), (0, slice(0, 5, None))),),
(((1, slice(0, None, None)), (0, slice(5, 10, None))),),
(((2, slice(0, None, None)), (0, slice(0, 5, None))),),
(((2, slice(0, None, None)), (0, slice(5, 10, None))),),
(((3, slice(0, None, None)), (0, slice(0, 5, None))),),
(((3, slice(0, None, None)), (0, slice(5, 10, None))),)
]
assert result == expected
def test_rechunk_unknown_from_pandas():
dd = pytest.importorskip('dask.dataframe')
pd = pytest.importorskip('pandas')
arr = np.random.randn(50, 10)
x = dd.from_pandas(pd.DataFrame(arr), 2).values
result = x.rechunk((None, (5, 5)))
assert np.isnan(x.chunks[0]).all()
assert np.isnan(result.chunks[0]).all()
assert result.chunks[1] == (5, 5)
expected = da.from_array(arr, chunks=((25, 25), (10,))).rechunk((None, (5, 5)))
assert_eq(result, expected)
def test_rechunk_unknown_from_array():
dd = pytest.importorskip('dask.dataframe')
# pd = pytest.importorskip('pandas')
x = dd.from_array(da.ones(shape=(4, 4), chunks=(2, 2))).values
# result = x.rechunk({1: 5})
result = x.rechunk((None, 4))
assert np.isnan(x.chunks[0]).all()
assert np.isnan(result.chunks[0]).all()
assert x.chunks[1] == (4,)
assert_eq(x, result)
@pytest.mark.parametrize('x, chunks', [
(da.ones(shape=(50, 10), chunks=(25, 10)), (None, 5)),
(da.ones(shape=(50, 10), chunks=(25, 10)), {1: 5}),
(da.ones(shape=(50, 10), chunks=(25, 10)), (None, (5, 5))),
(da.ones(shape=(1000, 10), chunks=(5, 10)), (None, 5)),
(da.ones(shape=(1000, 10), chunks=(5, 10)), {1: 5}),
(da.ones(shape=(1000, 10), chunks=(5, 10)), (None, (5, 5))),
(da.ones(shape=(10, 10), chunks=(10, 10)), (None, 5)),
(da.ones(shape=(10, 10), chunks=(10, 10)), {1: 5}),
(da.ones(shape=(10, 10), chunks=(10, 10)), (None, (5, 5))),
(da.ones(shape=(10, 10), chunks=(10, 2)), (None, 5)),
(da.ones(shape=(10, 10), chunks=(10, 2)), {1: 5}),
(da.ones(shape=(10, 10), chunks=(10, 2)), (None, (5, 5))),
])
def test_rechunk_unknown(x, chunks):
dd = pytest.importorskip('dask.dataframe')
y = dd.from_array(x).values
result = y.rechunk(chunks)
expected = x.rechunk(chunks)
assert_chunks_match(result.chunks, expected.chunks)
assert_eq(result, expected)
def test_rechunk_unknown_explicit():
dd = pytest.importorskip('dask.dataframe')
x = da.ones(shape=(10, 10), chunks=(5, 2))
y = dd.from_array(x).values
result = y.rechunk(((float('nan'), float('nan')), (5, 5)))
expected = x.rechunk((None, (5, 5)))
assert_chunks_match(result.chunks, expected.chunks)
assert_eq(result, expected)
def assert_chunks_match(left, right):
for x, y in zip(left, right):
if np.isnan(x).any():
assert np.isnan(x).all()
else:
assert x == y
def test_rechunk_unknown_raises():
dd = pytest.importorskip('dask.dataframe')
x = dd.from_array(da.ones(shape=(10, 10), chunks=(5, 5))).values
with pytest.raises(ValueError):
x.rechunk((None, (5, 5, 5)))
def test_old_to_new_single():
old = ((float('nan'), float('nan')), (8,))
new = ((float('nan'), float('nan')), (4, 4))
result = _old_to_new(old, new)
expected = [[[(0, slice(0, None, None))], [(1, slice(0, None, None))]],
[[(0, slice(0, 4, None))], [(0, slice(4, 8, None))]]]
assert result == expected
def test_old_to_new():
old = ((float('nan'),), (10,))
new = ((float('nan'),), (5, 5))
result = _old_to_new(old, new)
expected = [[[(0, slice(0, None, None))]],
[[(0, slice(0, 5, None))], [(0, slice(5, 10, None))]]]
assert result == expected
def test_old_to_new_large():
old = (tuple([float('nan')] * 4), (10,))
new = (tuple([float('nan')] * 4), (5, 5))
result = _old_to_new(old, new)
expected = [[[(0, slice(0, None, None))],
[(1, slice(0, None, None))],
[(2, slice(0, None, None))],
[(3, slice(0, None, None))]],
[[(0, slice(0, 5, None))], [(0, slice(5, 10, None))]]]
assert result == expected
def test_changing_raises():
nan = float('nan')
with pytest.raises(ValueError) as record:
_old_to_new(((nan, nan), (4, 4)), ((nan, nan, nan), (4, 4)))
assert 'unchanging' in str(record.value)
def test_old_to_new_known():
old = ((10, 10, 10, 10, 10), )
new = ((25, 5, 20), )
result = _old_to_new(old, new)
expected = [[[(0, slice(0, 10, None)), (1, slice(0, 10, None)), (2, slice(0, 5, None))],
[(2, slice(5, 10, None))],
[(3, slice(0, 10, None)), (4, slice(0, 10, None))]]]
assert result == expected
def test_rechunk_zero_dim():
da = pytest.importorskip('dask.array')
x = da.ones((0, 10, 100), chunks=(0, 10, 10)).rechunk((0, 10, 50))
assert len(x.compute()) == 0
def test_rechunk_avoid_needless_chunking():
x = da.ones(16, chunks=2)
y = x.rechunk(8)
dsk = y.__dask_graph__()
assert len(dsk) <= 8 + 2
@pytest.mark.parametrize('shape,chunks,bs,expected', [
(100, 1, 10, (10,) * 10),
(100, 50, 10, (10,) * 10),
(100, 100, 10, (10,) * 10),
(20, 7, 10, (7, 7, 6)),
(20, (1, 1, 1, 1, 6, 2, 1, 7), 5, (5, 5, 5, 5)),
])
def test_rechunk_auto_1d(shape, chunks, bs, expected):
x = da.ones(shape, chunks=(chunks,))
y = x.rechunk({0: 'auto'}, block_size_limit=bs * x.dtype.itemsize)
assert y.chunks == (expected,)
def test_rechunk_auto_2d():
x = da.ones((20, 20), chunks=(2, 2))
y = x.rechunk({0: -1, 1: "auto"}, block_size_limit=20 * x.dtype.itemsize)
assert y.chunks == ((20,), (1,) * 20)
x = da.ones((20, 20), chunks=(2, 2))
y = x.rechunk((-1, 'auto'), block_size_limit=80 * x.dtype.itemsize)
assert y.chunks == ((20,), (4,) * 5)
x = da.ones((20, 20), chunks=((2, 2)))
y = x.rechunk({0: 'auto'}, block_size_limit=20 * x.dtype.itemsize)
assert y.chunks[1] == x.chunks[1]
assert y.chunks[0] == (10, 10)
x = da.ones((20, 20), chunks=((2,) * 10, (2, 2, 2, 2, 2, 5, 5)))
y = x.rechunk({0: 'auto'}, block_size_limit=20 * x.dtype.itemsize)
assert y.chunks[1] == x.chunks[1]
assert y.chunks[0] == (4, 4, 4, 4, 4) # limited by largest
def test_rechunk_auto_3d():
x = da.ones((20, 20, 20), chunks=((2, 2, 2)))
y = x.rechunk({0: 'auto', 1: 'auto'}, block_size_limit=200 * x.dtype.itemsize)
assert y.chunks[2] == x.chunks[2]
assert y.chunks[0] == (10, 10)
assert y.chunks[1] == (10, 10) # even split
@pytest.mark.parametrize('n', [100, 1000])
def test_rechunk_auto_image_stack(n):
with dask.config.set({'array.chunk-size': '10MiB'}):
x = da.ones((n, 1000, 1000), chunks=(1, 1000, 1000), dtype='uint8')
y = x.rechunk('auto')
assert y.chunks == ((10,) * (n // 10), (1000,), (1000,))
assert y.rechunk('auto').chunks == y.chunks # idempotent
with dask.config.set({'array.chunk-size': '7MiB'}):
z = x.rechunk('auto')
assert z.chunks == ((5,) * (n // 5), (1000,), (1000,))
with dask.config.set({'array.chunk-size': '1MiB'}):
x = da.ones((n, 1000, 1000), chunks=(1, 1000, 1000), dtype='float64')
z = x.rechunk('auto')
assert z.chunks == ((1,) * n , (250,) * 4, (250,) * 4)
def test_rechunk_down():
with dask.config.set({'array.chunk-size': '10MiB'}):
x = da.ones((100, 1000, 1000), chunks=(1, 1000, 1000), dtype='uint8')
y = x.rechunk('auto')
assert y.chunks == ((10,) * 10, (1000,), (1000,))
with dask.config.set({'array.chunk-size': '1MiB'}):
z = y.rechunk('auto')
assert z.chunks == ((5,) * 20, (250,) * 4, (250,) * 4)
with dask.config.set({'array.chunk-size': '1MiB'}):
z = y.rechunk({0: 'auto'})
assert z.chunks == ((1,) * 100, (1000,), (1000,))
z = y.rechunk({1: 'auto'})
assert z.chunks == ((10,) * 10, (100,) * 10, (1000,))
def test_rechunk_zero():
with dask.config.set({'array.chunk-size': '1B'}):
x = da.ones(10, chunks=(5,))
y = x.rechunk('auto')
assert y.chunks == ((1,) * 10,)
def test_rechunk_bad_keys():
x = da.zeros((2, 3, 4), chunks=1)
assert x.rechunk({-1: 4}).chunks == ((1, 1), (1, 1, 1), (4,))
assert x.rechunk({-x.ndim: 2}).chunks == ((2,), (1, 1, 1), (1, 1, 1, 1))
with pytest.raises(TypeError) as info:
x.rechunk({'blah': 4})
assert 'blah' in str(info.value)
with pytest.raises(ValueError) as info:
x.rechunk({100: 4})
assert '100' in str(info.value)
with pytest.raises(ValueError) as info:
x.rechunk({-100: 4})
assert '-100' in str(info.value)