def isneginf(x, y=None): """ Return True where x is -infinity, and False otherwise. Parameters ---------- x : array_like The input array. y : array_like A boolean array with the same shape as `x` to store the result. Returns ------- y : ndarray A boolean array where y[i] = True only if x[i] = -Inf. See Also -------- isposinf, isfinite Examples -------- >>> np.isneginf([-np.inf, 0., np.inf]) array([ True, False, False], dtype=bool) """ if y is None: x = nx.asarray(x) y = nx.empty(x.shape, dtype=nx.bool_) nx.logical_and(nx.isinf(x), nx.signbit(x), y) return y
def isneginf(x, out=None): """ Test element-wise for negative infinity, return result as bool array. Parameters ---------- x : array_like The input array. out : array_like, optional A boolean array with the same shape and type as `x` to store the result. Returns ------- out : ndarray A boolean array with the same dimensions as the input. If second argument is not supplied then a numpy boolean array is returned with values True where the corresponding element of the input is negative infinity and values False where the element of the input is not negative infinity. If a second argument is supplied the result is stored there. If the type of that array is a numeric type the result is represented as zeros and ones, if the type is boolean then as False and True. The return value `out` is then a reference to that array. See Also -------- isinf, isposinf, isnan, isfinite Notes ----- NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). Errors result if the second argument is also supplied when x is a scalar input, or if first and second arguments have different shapes. Examples -------- >>> np.isneginf(np.NINF) array(True, dtype=bool) >>> np.isneginf(np.inf) array(False, dtype=bool) >>> np.isneginf(np.PINF) array(False, dtype=bool) >>> np.isneginf([-np.inf, 0., np.inf]) array([ True, False, False]) >>> x = np.array([-np.inf, 0., np.inf]) >>> y = np.array([2, 2, 2]) >>> np.isneginf(x, y) array([1, 0, 0]) >>> y array([1, 0, 0]) """ return nx.logical_and(nx.isinf(x), nx.signbit(x), out)
def isneginf(x, out=None): """ Test element-wise for negative infinity, return result as bool array. Parameters ---------- x : array_like The input array. out : array_like, optional A boolean array with the same shape and type as `x` to store the result. Returns ------- out : ndarray A boolean array with the same dimensions as the input. If second argument is not supplied then a numpy boolean array is returned with values True where the corresponding element of the input is negative infinity and values False where the element of the input is not negative infinity. If a second argument is supplied the result is stored there. If the type of that array is a numeric type the result is represented as zeros and ones, if the type is boolean then as False and True. The return value `out` is then a reference to that array. See Also -------- isinf, isposinf, isnan, isfinite Notes ----- NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). Errors result if the second argument is also supplied when x is a scalar input, or if first and second arguments have different shapes. Examples -------- >>> np.isneginf(np.NINF) array(True, dtype=bool) >>> np.isneginf(np.inf) array(False, dtype=bool) >>> np.isneginf(np.PINF) array(False, dtype=bool) >>> np.isneginf([-np.inf, 0., np.inf]) array([ True, False, False], dtype=bool) >>> x = np.array([-np.inf, 0., np.inf]) >>> y = np.array([2, 2, 2]) >>> np.isneginf(x, y) array([1, 0, 0]) >>> y array([1, 0, 0]) """ return nx.logical_and(nx.isinf(x), nx.signbit(x), out)
def isneginf(x, out=None): """ Test element-wise for negative infinity, return result as bool array. Parameters ---------- x : array_like The input array. out : array_like, optional A location into which the result is stored. If provided, it must have a shape that the input broadcasts to. If not provided or None, a freshly-allocated boolean array is returned. Returns ------- out : ndarray A boolean array with the same dimensions as the input. If second argument is not supplied then a numpy boolean array is returned with values True where the corresponding element of the input is negative infinity and values False where the element of the input is not negative infinity. If a second argument is supplied the result is stored there. If the type of that array is a numeric type the result is represented as zeros and ones, if the type is boolean then as False and True. The return value `out` is then a reference to that array. See Also -------- isinf, isposinf, isnan, isfinite Notes ----- NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). Errors result if the second argument is also supplied when x is a scalar input, if first and second arguments have different shapes, or if the first argument has complex values. Examples -------- >>> np.isneginf(np.NINF) True >>> np.isneginf(np.inf) False >>> np.isneginf(np.PINF) False >>> np.isneginf([-np.inf, 0., np.inf]) array([ True, False, False]) >>> x = np.array([-np.inf, 0., np.inf]) >>> y = np.array([2, 2, 2]) >>> np.isneginf(x, y) array([1, 0, 0]) >>> y array([1, 0, 0]) """ is_inf = nx.isinf(x) try: signbit = nx.signbit(x) except TypeError as e: dtype = nx.asanyarray(x).dtype raise TypeError(f'This operation is not supported for {dtype} values ' 'because it would be ambiguous.') from e else: return nx.logical_and(is_inf, signbit, out)
def isposinf(x, out=None): """ Test element-wise for positive infinity, return result as bool array. Parameters ---------- x : array_like The input array. y : array_like, optional A boolean array with the same shape as `x` to store the result. Returns ------- out : ndarray A boolean array with the same dimensions as the input. If second argument is not supplied then a boolean array is returned with values True where the corresponding element of the input is positive infinity and values False where the element of the input is not positive infinity. If a second argument is supplied the result is stored there. If the type of that array is a numeric type the result is represented as zeros and ones, if the type is boolean then as False and True. The return value `out` is then a reference to that array. See Also -------- isinf, isneginf, isfinite, isnan Notes ----- NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). Errors result if the second argument is also supplied when x is a scalar input, if first and second arguments have different shapes, or if the first argument has complex values Examples -------- >>> np.isposinf(np.PINF) array(True, dtype=bool) >>> np.isposinf(np.inf) array(True, dtype=bool) >>> np.isposinf(np.NINF) array(False, dtype=bool) >>> np.isposinf([-np.inf, 0., np.inf]) array([False, False, True]) >>> x = np.array([-np.inf, 0., np.inf]) >>> y = np.array([2, 2, 2]) >>> np.isposinf(x, y) array([0, 0, 1]) >>> y array([0, 0, 1]) """ is_inf = nx.isinf(x) try: signbit = ~nx.signbit(x) except TypeError: raise TypeError('This operation is not supported for complex values ' 'because it would be ambiguous.') else: return nx.logical_and(is_inf, signbit, out)
def isposinf(x, out=None): """ Test element-wise for positive infinity, return result as bool array. Parameters ---------- x : array_like The input array. y : array_like, optional A boolean array with the same shape as `x` to store the result. Returns ------- out : ndarray A boolean array with the same dimensions as the input. If second argument is not supplied then a boolean array is returned with values True where the corresponding element of the input is positive infinity and values False where the element of the input is not positive infinity. If a second argument is supplied the result is stored there. If the type of that array is a numeric type the result is represented as zeros and ones, if the type is boolean then as False and True. The return value `out` is then a reference to that array. See Also -------- isinf, isneginf, isfinite, isnan Notes ----- NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). Errors result if the second argument is also supplied when x is a scalar input, if first and second arguments have different shapes, or if the first argument has complex values Examples -------- >>> np.isposinf(np.PINF) True >>> np.isposinf(np.inf) True >>> np.isposinf(np.NINF) False >>> np.isposinf([-np.inf, 0., np.inf]) array([False, False, True]) >>> x = np.array([-np.inf, 0., np.inf]) >>> y = np.array([2, 2, 2]) >>> np.isposinf(x, y) array([0, 0, 1]) >>> y array([0, 0, 1]) """ is_inf = nx.isinf(x) try: signbit = ~nx.signbit(x) except TypeError: raise TypeError('This operation is not supported for complex values ' 'because it would be ambiguous.') else: return nx.logical_and(is_inf, signbit, out)
def isposinf(x, y=None): """ Shows which elements of the input are positive infinity. Returns a numpy array resulting from an element-wise test for positive infinity. Parameters ---------- x : array_like The input array. y : array_like A boolean array with the same shape as `x` to store the result. Returns ------- y : ndarray A numpy boolean array with the same dimensions as the input. If second argument is not supplied then a numpy boolean array is returned with values True where the corresponding element of the input is positive infinity and values False where the element of the input is not positive infinity. If second argument is supplied then an numpy integer array is returned with values 1 where the corresponding element of the input is positive positive infinity. See Also -------- isinf : Shows which elements are negative or positive infinity. isneginf : Shows which elements are negative infinity. isnan : Shows which elements are Not a Number (NaN). isfinite: Shows which elements are not: Not a number, positive and negative infinity Notes ----- Numpy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). This means that Not a Number is not equivalent to infinity. Also that positive infinity is not equivalent to negative infinity. But infinity is equivalent to positive infinity. Errors result if second argument is also supplied with scalar input or if first and second arguments have different shapes. Numpy's definitions for positive infinity (PINF) and negative infinity (NINF) may be change in the future versions. Examples -------- >>> np.isposinf(np.PINF) array(True, dtype=bool) >>> np.isposinf(np.inf) array(True, dtype=bool) >>> np.isposinf(np.NINF) array(False, dtype=bool) >>> np.isposinf([-np.inf, 0., np.inf]) array([False, False, True], dtype=bool) >>> x=np.array([-np.inf, 0., np.inf]) >>> y=np.array([2,2,2]) >>> np.isposinf(x,y) array([1, 0, 0]) >>> y array([1, 0, 0]) """ if y is None: x = nx.asarray(x) y = nx.empty(x.shape, dtype=nx.bool_) nx.logical_and(nx.isinf(x), ~nx.signbit(x), y) return y