def nanvar(a,
axis: Optional[Union[int, Tuple[int, ...]]] = None,
dtype=None,
out=None,
ddof=0,
keepdims=False,
where=None):
_check_arraylike("nanvar", a)
lax_internal._check_user_dtype_supported(dtype, "nanvar")
if out is not None:
raise NotImplementedError(
"The 'out' argument to jnp.nanvar is not supported.")
a_dtype, dtype = _var_promote_types(dtypes.dtype(a), dtype)
a_mean = nanmean(a, axis, dtype=a_dtype, keepdims=True, where=where)
centered = _where(lax_internal._isnan(a), 0,
a - a_mean) # double-where trick for gradients.
if dtypes.issubdtype(centered.dtype, np.complexfloating):
centered = lax.real(lax.mul(centered, lax.conj(centered)))
else:
centered = lax.square(centered)
normalizer = sum(lax_internal.bitwise_not(lax_internal._isnan(a)),
axis=axis,
keepdims=keepdims,
where=where)
normalizer = normalizer - ddof
normalizer_mask = lax.le(normalizer, 0)
result = sum(centered, axis, keepdims=keepdims, where=where)
result = _where(normalizer_mask, np.nan, result)
divisor = _where(normalizer_mask, 1, normalizer)
out = lax.div(result, lax.convert_element_type(divisor, result.dtype))
return lax.convert_element_type(out, dtype)
def _normalize_float(x): info = dtypes.finfo(dtypes.dtype(x)) cond = lax.abs(x) < info.tiny x1 = _where(cond, x * _lax_const(x, 1 << info.nmant), x) x2 = _where(cond, lax.full_like(x, -info.nmant, dtype=np.int32), lax.full_like(x, 0, dtype=np.int32)) int_type = _INT_DTYPES[info.bits] return lax.bitcast_convert_type(x1, int_type), x2
def _normalize_float(x):
info = dtypes.finfo(dtypes.dtype(x))
int_type = _INT_DTYPES[info.bits]
cond = lax.abs(x) < info.tiny
x1 = _where(cond, x * _lax_const(x, 1 << info.nmant), x)
x2 = _where(cond, int_type(-info.nmant), int_type(0))
return lax.bitcast_convert_type(x1, int_type), x2
def sinc(x):
_check_arraylike("sinc", x)
x, = _promote_dtypes_inexact(x)
eq_zero = lax.eq(x, _lax_const(x, 0))
pi_x = lax.mul(_lax_const(x, np.pi), x)
safe_pi_x = _where(eq_zero, _lax_const(x, 1), pi_x)
return _where(eq_zero, _sinc_maclaurin(0, pi_x),
lax.div(lax.sin(safe_pi_x), safe_pi_x))
def _roots_with_zeros(p, num_leading_zeros):
# Avoid lapack errors when p is all zero
p = _where(len(p) == num_leading_zeros, 1.0, p)
# Roll any leading zeros to the end & compute the roots
roots = _roots_no_zeros(roll(p, -num_leading_zeros))
# Sort zero roots to the end.
roots = lax.sort_key_val(roots == 0, roots)[1]
# Set roots associated with num_leading_zeros to NaN
return _where(
arange(roots.size) < roots.size - num_leading_zeros, roots,
complex(np.nan, np.nan))
def arccosh(x):
# Note: arccosh is multi-valued for complex input, and lax.acosh uses a different
# convention than np.arccosh.
out = lax.acosh(*_promote_args_inexact("arccosh", x))
if dtypes.issubdtype(out.dtype, np.complexfloating):
out = _where(real(out) < 0, lax.neg(out), out)
return out
def _cumulative_reduction(a,
axis: Optional[Union[int, Tuple[int,
...]]] = None,
dtype=None,
out=None):
_check_arraylike(np_reduction.__name__, a)
if out is not None:
raise NotImplementedError(
f"The 'out' argument to jnp.{np_reduction.__name__} "
f"is not supported.")
lax_internal._check_user_dtype_supported(dtype, np_reduction.__name__)
if axis is None or _isscalar(a):
a = lax.reshape(a, (np.size(a), ))
axis = 0
a_shape = list(np.shape(a))
num_dims = len(a_shape)
axis = _canonicalize_axis(axis, num_dims)
if fill_nan:
a = _where(lax_internal._isnan(a), _lax_const(a, fill_value), a)
if not dtype and dtypes.dtype(a) == np.bool_:
dtype = dtypes.canonicalize_dtype(dtypes.int_)
if dtype:
a = lax.convert_element_type(a, dtype)
return reduction(a, axis)
def modf(x, out=None):
_check_arraylike("modf", x)
if out is not None:
raise NotImplementedError(
"The 'out' argument to jnp.modf is not supported.")
whole = _where(lax.ge(x, lax_internal._zero(x)), floor(x), ceil(x))
return x - whole, whole
def ldexp(x1, x2):
_check_arraylike("ldexp", x1, x2)
x1_dtype = dtypes.dtype(x1)
x2_dtype = dtypes.dtype(x2)
if (dtypes.issubdtype(x1_dtype, np.complexfloating)
or dtypes.issubdtype(x2_dtype, np.inexact)):
raise ValueError(
f"ldexp not supported for input types {(x1_dtype, x2_dtype)}")
x1, x2 = _promote_shapes("ldexp", x1, x2)
dtype = dtypes.canonicalize_dtype(dtypes._to_inexact_dtype(x1_dtype))
info = dtypes.finfo(dtype)
int_type = _INT_DTYPES[info.bits]
x1 = lax.convert_element_type(x1, dtype)
x2 = lax.convert_element_type(x2, int_type)
mask = (1 << info.nexp) - 1
bias = ((1 << info.nexp) - 1) >> 1
x, e = _normalize_float(x1)
x2 += e + ((x >> info.nmant) & mask) - bias
# find underflow/overflow before denormalization
underflow_cond = x2 < -(bias + info.nmant)
overflow_cond = x2 > bias
m = lax.full_like(x, 1, dtype=dtype)
# denormals
cond = x2 < -bias + 1
x2 = _where(cond, x2 + info.nmant, x2)
m = _where(cond, m / (1 << info.nmant), m)
x2 = lax.convert_element_type(x2, np.int32)
x &= ~(mask << info.nmant)
x |= ((lax.convert_element_type(x2, int_type) + bias) << info.nmant)
x = lax.convert_element_type(m, dtype) * lax.bitcast_convert_type(x, dtype)
# underflow
x = _where(underflow_cond, lax.full_like(x, 0, dtype=dtype), x)
# overflow
x = _where(overflow_cond, lax.sign(x1) * lax.full_like(x, np.inf), x)
# ldexp(x1, x2) = x1 for x1 = inf, -inf, nan, 0
return _where(isinf(x1) | isnan(x1) | (x1 == 0), x1, x)
def sign(x):
_check_arraylike('sign', x)
dtype = dtypes.dtype(x)
if dtypes.issubdtype(dtype, np.complexfloating):
re = lax.real(x)
return lax.complex(lax.sign(_where(re != 0, re, lax.imag(x))),
_constant_like(re, 0))
return lax.sign(x)
def _power(x1, x2):
x1, x2 = _promote_args("power", x1, x2)
dtype = dtypes.dtype(x1)
if not dtypes.issubdtype(dtype, np.integer):
return lax.pow(x1, x2)
# Integer power => use binary exponentiation.
# TODO(phawkins): add integer pow support to XLA.
bits = 6 # Anything more would overflow for any x1 > 1
zero = _constant_like(x2, 0)
one = _constant_like(x2, 1)
# Initialize acc carefully such that pow(0, x2) is zero for x2 != 0
acc = _where(lax.bitwise_and(lax.eq(x1, zero), lax.ne(x2, zero)), zero, one)
for _ in range(bits):
acc = _where(lax.bitwise_and(x2, one), lax.mul(acc, x1), acc)
x1 = lax.mul(x1, x1)
x2 = lax.shift_right_logical(x2, one)
return acc
def frexp(x):
_check_arraylike("frexp", x)
x, = _promote_dtypes_inexact(x)
if dtypes.issubdtype(x.dtype, np.complexfloating):
raise TypeError("frexp does not support complex-valued inputs")
dtype = dtypes.dtype(x)
info = dtypes.finfo(dtype)
mask = (1 << info.nexp) - 1
bias = ((1 << info.nexp) - 1) >> 1
x1, x2 = _normalize_float(x)
x2 += ((x1 >> info.nmant) & mask) - bias + 1
x1 &= ~(mask << info.nmant)
x1 |= (bias - 1) << info.nmant
x1 = lax.bitcast_convert_type(x1, dtype)
cond = isinf(x) | isnan(x) | (x == 0)
x2 = _where(cond, lax_internal._zeros(x2), x2)
return _where(cond, x, x1), lax.convert_element_type(x2, np.int32)
def floor_divide(x1, x2):
x1, x2 = _promote_args("floor_divide", x1, x2)
dtype = dtypes.dtype(x1)
if dtypes.issubdtype(dtype, np.integer):
quotient = lax.div(x1, x2)
select = logical_and(lax.sign(x1) != lax.sign(x2), lax.rem(x1, x2) != 0)
# TODO(mattjj): investigate why subtracting a scalar was causing promotion
return _where(select, quotient - 1, quotient)
elif dtypes.issubdtype(dtype, np.complexfloating):
x1r = lax.real(x1)
x1i = lax.imag(x1)
x2r = lax.real(x2)
x2i = lax.imag(x2)
which = lax.ge(lax.abs(x2r), lax.abs(x2i))
rat1 = _where(which, lax.full_like(x2i, 1), lax.div(x2r, x2i))
rat2 = _where(which, lax.div(x2i, x2r), _lax_const(x2i, 1))
out = lax.floor(lax.div(lax.add(lax.mul(x1r, rat1), lax.mul(x1i, rat2)),
lax.add(lax.mul(x2r, rat1), lax.mul(x2i, rat2))))
return lax.convert_element_type(out, dtype)
else:
return _float_divmod(x1, x2)[0]
def ldexp(x1, x2):
_check_arraylike("ldexp", x1, x2)
dtype = dtypes.canonicalize_dtype(_result_dtype(np.ldexp, x1, x2))
x1, x2 = _promote_shapes("ldexp", x1, x2)
x1 = lax.convert_element_type(x1, dtype)
info = dtypes.finfo(dtype)
mask = (1 << info.nexp) - 1
bias = ((1 << info.nexp) - 1) >> 1
int_type = _INT_DTYPES[info.bits]
x, e = _normalize_float(x1)
x2 += e + ((x >> info.nmant) & mask) - bias
# find underflow/overflow before denormalization
underflow_cond = x2 < -(bias + info.nmant)
overflow_cond = x2 > bias
m = lax.full_like(x, 1, dtype=dtype)
# denormals
cond = x2 < -bias + 1
x2 = _where(cond, x2 + info.nmant, x2)
m = _where(cond, m / (1 << info.nmant), m)
x2 = lax.convert_element_type(x2, np.int32)
x &= ~(mask << info.nmant)
x |= ((lax.convert_element_type(x2, int_type) + bias) << info.nmant)
x = lax.convert_element_type(m, dtype) * lax.bitcast_convert_type(x, dtype)
# underflow
x = _where(underflow_cond, lax.full_like(x, 0, dtype=dtype), x)
# overflow
x = _where(overflow_cond, lax.sign(x1) * lax.full_like(x, np.inf), x)
# ldexp(x1, x2) = x1 for x1 = inf, -inf, nan, 0
return _where(isinf(x1) | isnan(x1) | (x1 == 0), x1, x)
def _nan_reduction(a,
name,
jnp_reduction,
init_val,
nan_if_all_nan,
axis=None,
keepdims=None,
**kwargs):
_check_arraylike(name, a)
if not dtypes.issubdtype(dtypes.dtype(a), np.inexact):
return jnp_reduction(a, axis=axis, keepdims=keepdims, **kwargs)
out = jnp_reduction(_where(lax_internal._isnan(a),
_reduction_init_val(a, init_val), a),
axis=axis,
keepdims=keepdims,
**kwargs)
if nan_if_all_nan:
return _where(
all(lax_internal._isnan(a), axis=axis, keepdims=keepdims),
_lax_const(a, np.nan), out)
else:
return out
def roots(p, *, strip_zeros=True):
_check_arraylike("roots", p)
p = atleast_1d(*_promote_dtypes_inexact(p))
if p.ndim != 1:
raise ValueError("Input must be a rank-1 array.")
if p.size < 2:
return array([], dtype=dtypes._to_complex_dtype(p.dtype))
num_leading_zeros = _where(all(p == 0), len(p), argmin(p == 0))
if strip_zeros:
num_leading_zeros = core.concrete_or_error(
int, num_leading_zeros,
"The error occurred in the jnp.roots() function. To use this within a "
"JIT-compiled context, pass strip_zeros=False, but be aware that leading zeros "
"will be result in some returned roots being set to NaN.")
return _roots_no_zeros(p[num_leading_zeros:])
else:
return _roots_with_zeros(p, num_leading_zeros)
def _reduction(a,
name,
np_fun,
op,
init_val,
has_identity=True,
preproc=None,
bool_op=None,
upcast_f16_for_computation=False,
axis=None,
dtype=None,
out=None,
keepdims=False,
initial=None,
where_=None,
parallel_reduce=None):
bool_op = bool_op or op
# Note: we must accept out=None as an argument, because numpy reductions delegate to
# object methods. For example `np.sum(x)` will call `x.sum()` if the `sum()` method
# exists, passing along all its arguments.
if out is not None:
raise NotImplementedError(
f"The 'out' argument to jnp.{name} is not supported.")
_check_arraylike(name, a)
lax_internal._check_user_dtype_supported(dtype, name)
axis = core.concrete_or_error(None, axis,
f"axis argument to jnp.{name}().")
if initial is None and not has_identity and where_ is not None:
raise ValueError(
f"reduction operation {name} does not have an identity, so to use a "
f"where mask one has to specify 'initial'")
a = a if isinstance(a, ndarray) else _asarray(a)
a = preproc(a) if preproc else a
pos_dims, dims = _reduction_dims(a, axis)
if initial is None and not has_identity:
shape = np.shape(a)
if not _all(core.greater_equal_dim(shape[d], 1) for d in pos_dims):
raise ValueError(
f"zero-size array to reduction operation {name} which has no identity"
)
result_dtype = dtypes.canonicalize_dtype(
dtype or dtypes.dtype(np_fun(np.ones((), dtype=dtypes.dtype(a)))))
if upcast_f16_for_computation and dtypes.issubdtype(
result_dtype, np.inexact):
computation_dtype = _upcast_f16(result_dtype)
else:
computation_dtype = result_dtype
a = lax.convert_element_type(a, computation_dtype)
op = op if computation_dtype != np.bool_ else bool_op
# NB: in XLA, init_val must be an identity for the op, so the user-specified
# initial value must be applied afterward.
init_val = _reduction_init_val(a, init_val)
if where_ is not None:
a = _where(where_, a, init_val)
if pos_dims is not dims:
if parallel_reduce is None:
raise NotImplementedError(
f"Named reductions not implemented for jnp.{name}()")
result = parallel_reduce(a, dims)
else:
result = lax.reduce(a, init_val, op, dims)
if initial is not None:
result = op(lax.convert_element_type(initial, a.dtype), result)
if keepdims:
result = lax.expand_dims(result, pos_dims)
return lax.convert_element_type(result, dtype or result_dtype)
def heaviside(x1, x2):
_check_arraylike("heaviside", x1, x2)
x1, x2 = _promote_dtypes_inexact(x1, x2)
zero = _lax_const(x1, 0)
return _where(lax.lt(x1, zero), zero,
_where(lax.gt(x1, zero), _lax_const(x1, 1), x2))
def fmod(x1, x2):
_check_arraylike("fmod", x1, x2)
if dtypes.issubdtype(dtypes.result_type(x1, x2), np.integer):
x2 = _where(x2 == 0, lax_internal._ones(x2), x2)
return lax.rem(*_promote_args("fmod", x1, x2))
def copysign(x1, x2):
x1, x2 = _promote_args_inexact("copysign", x1, x2)
if dtypes.issubdtype(dtypes.dtype(x1), np.complexfloating):
raise TypeError("copysign does not support complex-valued inputs")
return _where(signbit(x2).astype(bool), -lax.abs(x1), lax.abs(x1))
