8000 ENH: Improve error message in multinomial by bashtage · Pull Request #18482 · numpy/numpy · GitHub
[go: up one dir, main page]
Skip to content

ENH: Improve error message in multinomial #18482

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Feb 27, 2021
Merged

ENH: Improve error message in multinomial #18482

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
9e068f4
ENH: Improve error message in multinomial
bashtage Jul 2, 2020
2ee92e2
Accept suggestion
bashtage Feb 24, 2021
e900be2
Address comments
Feb 26, 2021
b1015ad
Port error to RandomState
Feb 26, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 14 additions & 1 deletion numpy/random/_generator.pyx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3756,7 +3756,20 @@ cdef class Generator:
pix = <double*>np.PyArray_DATA(parr)
check_array_constraint(parr, 'pvals', CONS_BOUNDED_0_1)
if kahan_sum(pix, d-1) > (1.0 + 1e-12):
raise ValueError("sum(pvals[:-1]) > 1.0")
# When floating, but not float dtype, and close, improve the error
# 1.0001 works for float16 and float32
if (isinstance(pvals, np.ndarray)
and np.issubdtype(pvals.dtype, np.floating)
and pvals.dtype != float
and pvals.sum() < 1.0001):
msg = ("sum(pvals[:-1].astype(np.float64)) > 1.0. The pvals "
"array is cast to 64-bit floating point prior to "
"checking the sum. Precision changes when casting may "
"cause problems even if the sum of the original pvals "
"is valid.")
else:
msg = "sum(pvals[:-1]) > 1.0"
raise ValueError(msg)

if np.PyArray_NDIM(on) != 0: # vector
check_array_constraint(on, 'n', CONS_NON_NEGATIVE)
Expand Down
15 changes: 14 additions & 1 deletion numpy/random/mtrand.pyx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4232,7 +4232,20 @@ cdef class RandomState:
pix = <double*>np.PyArray_DATA(parr)
check_array_constraint(parr, 'pvals', CONS_BOUNDED_0_1)
if kahan_sum(pix, d-1) > (1.0 + 1e-12):
raise ValueError("sum(pvals[:-1]) > 1.0")
# When floating, but not float dtype, and close, improve the error
# 1.0001 works for float16 and float32
if (isinstance(pvals, np.ndarray)
and np.issubdtype(pvals.dtype, np.floating)
and pvals.dtype != float
and pvals.sum() < 1.0001):
msg = ("sum(pvals[:-1].astype(np.float64)) > 1.0. The pvals "
"array is cast to 64-bit floating point prior to "
"checking the sum. Precision changes when casting may "
"cause problems even if the sum of the original pvals "
"is valid.")
else:
msg = "sum(pvals[:-1]) > 1.0"
raise ValueError(msg)

if size is None:
shape = (d,)
Expand Down
8 changes: 8 additions & 0 deletions numpy/random/tests/test_generator_mt19937.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -142,6 +142,14 @@ def test_multidimensional_pvals(self):
assert_raises(ValueError, random.multinomial, 10, [[[0], [1]], [[1], [0]]])
assert_raises(ValueError, random.multinomial, 10, np.array([[0, 1], [1, 0]]))

def test_multinomial_pvals_float32(self):
x = np.array([9.9e-01, 9.9e-01, 1.0e-09, 1.0e-09, 1.0e-09, 1.0e-09,
1.0e-09, 1.0e-09, 1.0e-09, 1.0e-09], dtype=np.float32)
pvals = x / x.sum()
random = Generator(MT19937(1432985819))
match = r"[\w\s]*pvals array is cast to 64-bit floating"
with pytest.raises(ValueError, match=match):
random.multinomial(1, pvals)

class TestMultivariateHypergeometric:

Expand Down
8 changes: 8 additions & 0 deletions numpy/random/tests/test_randomstate.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -167,6 +167,14 @@ def test_p_non_contiguous(self):
contig = random.multinomial(100, pvals=np.ascontiguousarray(pvals))
assert_array_equal(non_contig, contig)

def test_multinomial_pvals_float32(self):
x = np.array([9.9e-01, 9.9e-01, 1.0e-09, 1.0e-09, 1.0e-09, 1.0e-09,
1.0e-09, 1.0e-09, 1.0e-09, 1.0e-09], dtype=np.float32)
pvals = x / x.sum()
match = r"[\w\s]*pvals array is cast to 64-bit floating"
with pytest.raises(ValueError, match=match):
random.multinomial(1, pvals)


class TestSetState:
def setup(self):
Expand Down
0