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BUG: Broadcast Arguments in Random Integer Generation #6902

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BUG: Broadcast Arguments in Random Integer Generation #6902

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152 changes: 119 additions & 33 deletions numpy/random/mtrand/mtrand.pyx
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Original file line number Diff line number Diff line change
Expand Up @@ -547,6 +547,95 @@ cdef object discd_array(rk_state *state, rk_discd func, object size, ndarray oa,
PyArray_MultiIter_NEXTi(multi, 1)
return array

cdef object gen_randint_array(rk_state *state, object low, object high,
object size, object lock, npy_intp is_half_open):
cdef ndarray lo, hi
cdef long lnlo, lnhi

lnlo = PyInt_AsLong(low)
lnhi = PyInt_AsLong(high)

err_msg = "low >= high" if is_half_open else "low > high"

if not PyErr_Occurred():
if lnlo > lnhi - <long>is_half_open:
raise ValueError(err_msg)

return randint_array_sc(state, lnlo, lnhi, size, lock, is_half_open)

PyErr_Clear()

lo = <ndarray>PyArray_FROM_OTF(low, NPY_LONG, NPY_ARRAY_ALIGNED)
hi = <ndarray>PyArray_FROM_OTF(high, NPY_LONG, NPY_ARRAY_ALIGNED)

if np.any(np.less(np.subtract(hi, <long>is_half_open), lo)):
raise ValueError(err_msg)

return randint_array(state, lo, hi, size, lock, is_half_open)

cdef object randint_array_sc(rk_state *state, long low, long high,
object size, object lock, npy_intp is_half_open):
cdef long rv
cdef long *array_data
cdef unsigned long diff
cdef ndarray array "arrayObject"
cdef npy_intp length
cdef npy_intp i

diff = <unsigned long>high - <unsigned long>low - is_half_open
if size is None:
with lock:
rv = low + <long>rk_interval(diff, state)
return rv
else:
array = <ndarray>np.empty(size, int)
length = PyArray_SIZE(array)
array_data = <long *>PyArray_DATA(array)
with lock, nogil:
for i from 0 <= i < length:
rv = low + <long>rk_interval(diff, state)
array_data[i] = rv
return array

cdef object randint_array(rk_state *state, ndarray low, ndarray high,
object size, object lock, npy_intp is_half_open):
cdef long *low_data
cdef long *high_data
cdef long *array_data
cdef unsigned long diff
cdef ndarray array "arrayObject"
cdef broadcast multi
cdef npy_intp i

if size is None:
multi = <broadcast> PyArray_MultiIterNew(2, <void *>low, <void *>high)
array = <ndarray> PyArray_SimpleNew(multi.nd, multi.dimensions, NPY_LONG)
array_data = <long *>PyArray_DATA(array)
with lock, nogil:
for i from 0 <= i < multi.size:
low_data = <long *>PyArray_MultiIter_DATA(multi, 0)
high_data = <long *>PyArray_MultiIter_DATA(multi, 1)
diff = <unsigned long> high_data[0] - <unsigned long> low_data[0] \
- <unsigned long>is_half_open
array_data[i] = low_data[0] + <long>rk_interval(diff, state)
PyArray_MultiIter_NEXT(multi)
else:
array = <ndarray>np.empty(size, int)
array_data = <long *>PyArray_DATA(array)
multi = <broadcast> PyArray_MultiIterNew(3, <void *> array, <void *>low, <void *>high)
if (multi.size != PyArray_SIZE(array)):
raise ValueError("size is not compatible with inputs")
with lock, nogil:
for i from 0 <= i < multi.size:
low_data = <long *>PyArray_MultiIter_DATA(multi, 1)
high_data = <long *>PyArray_MultiIter_DATA(multi, 2)
diff = <unsigned long> high_data[0] - <unsigned long> low_data[0] \
- <unsigned long>is_half_open
array_data[i] = low_data[0] + <long>rk_interval(diff, state)
PyArray_MultiIter_NEXT(multi)

return array

cdef double kahan_sum(double *darr, npy_intp n):
cdef double c, y, t, sum
cdef npy_intp i
Expand Down Expand Up @@ -890,6 +979,9 @@ cdef class RandomState:
"half-open" interval [`low`, `high`). If `high` is None (the default),
then results are from [0, `low`).

This function can broadcast arguments, but if an array is passed in
for either `low` or `high`, all elements in the array must be integers.

Parameters
----------
low : int
Expand Down Expand Up @@ -923,6 +1015,15 @@ cdef class RandomState:
array([1, 0, 0, 0, 1, 1, 0, 0, 1, 0])
>>> np.random.randint(1, size=10)
array([0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
>>> np.random.randint(5, [11, 16, 25])
array([ 9, 6, 12])

Because the broadcasting requires that the array argument(s)
contain all integers, this is the function call that would
be equivalent to `np.random.random_integers(6, [18, None])`:

>>> np.random.randint([6, 0], [18, 6])
array([10, 5])

Generate a 2 x 4 array of ints between 0 and 4, inclusive:

Expand All @@ -931,14 +1032,12 @@ cdef class RandomState:
[3, 2, 2, 0]])

"""
if high is not None and low >= high:
raise ValueError("low >= high")

if high is None:
high = low
low = 0

return self.random_integers(low, high - 1, size)
return gen_randint_array(self.internal_state, low,
high, size, self.lock, 1)

def bytes(self, npy_intp length):
"""
Expand Down Expand Up @@ -1357,6 +1456,9 @@ cdef class RandomState:
closed interval [`low`, `high`]. If `high` is None (the default),
then results are from [1, `low`].

This function can broadcast arguments, but if an array is passed in
for either `low` or `high`, all elements in the array must be integers.

Parameters
----------
low : int
Expand Down Expand Up @@ -1400,6 +1502,15 @@ cdef class RandomState:
array([[5, 4],
[3, 3],
[4, 5]])
>>> np.random.random_integers(5, [10, 15, 20])
array([ 9, 11, 13])

Because the broadcasting requires that the array argument(s)
contain all integers, this is the function call that would
be equivalent to `np.random.random_integers(5, [10, None])`:

>>> np.random.random_integers([5, 1], [10, 5])
array([10, 4])

Choose five random numbers from the set of five evenly-spaced
numbers between 0 and 2.5, inclusive (*i.e.*, from the set
Expand All @@ -1421,37 +1532,12 @@ cdef class RandomState:
>>> plt.show()

"""
if high is not None and low > high:
raise ValueError("low > high")

cdef long lo, hi, rv
cdef unsigned long diff
cdef long *array_data
cdef ndarray array "arrayObject"
cdef npy_intp length
cdef npy_intp i

if high is None:
lo = 1
hi = low
else:
lo = low
hi = high
high = low
low = 1

diff = <unsigned long>hi - <unsigned long>lo
if size is None:
with self.lock:
rv = lo + <long>rk_interval(diff, self. internal_state)
return rv
else:
array = <ndarray>np.empty(size, int)
length = PyArray_SIZE(array)
array_data = <long *>PyArray_DATA(array)
with self.lock, nogil:
for i from 0 <= i < length:
rv = lo + <long>rk_interval(diff, self. internal_state)
array_data[i] = rv
return array
return gen_randint_array(self.internal_state, low,
high, size, self.lock, 0)

# Complicated, continuous distributions:
def standard_normal(self, size=None):
Expand Down
16 changes: 16 additions & 0 deletions numpy/random/tests/test_random.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,14 @@ def test_randint(self):
[-48, -66]])
np.testing.assert_array_equal(actual, desired)

def test_randint_can_broadcast(self):
# See Issue #6745
np.random.seed(self.seed)
actual = np.random.randint(-99, [9, 99, 999,
9999, 99999])
desired = np.array([-97, 3, 972, 1065, 69328])
np.testing.assert_array_equal(actual, desired)

def test_random_integers(self):
np.random.seed(self.seed)
actual = np.random.random_integers(-99, 99, size=(3, 2))
Expand All @@ -178,6 +186,14 @@ def test_random_integers_max_int(self):
desired = np.iinfo('l').max
np.testing.assert_equal(actual, desired)

def test_random_integers_can_broadcast(self):
# See Issue #6745
np.random.seed(self.seed)
actual = np.random.random_integers([-99999, -9999,
-999, -99, -9], 99)
desired = np.array([-12573, -3856, 72, 41, 42])
np.testing.assert_array_equal(actual, desired)

def test_random_sample(self):
np.random.seed(self.seed)
actual = np.random.random_sample((3, 2))
Expand Down