numpy.isinf¶
- numpy.isinf(x[, out]) = <ufunc 'isinf'>¶
Test element-wise for positive or negative infinity.
Returns a boolean array of the same shape as x, True where x == +/-inf, otherwise False.
Parameters: x : array_like
Input values
out : array_like, optional
An array with the same shape as x to store the result.
Returns: y : bool (scalar) or boolean ndarray
For scalar input, the result is a new boolean with value True if the input is positive or negative infinity; otherwise the value is False.
For array input, the result is a boolean array with the same shape as the input and the values are True where the corresponding element of the input is positive or negative infinity; elsewhere the values are False. If a second argument was 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, respectively. The return value y is then a reference to that array.
Notes
Numpy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
Errors result if the second argument is supplied when the first argument is a scalar, or if the first and second arguments have different shapes.
Examples
>>> np.isinf(np.inf) True >>> np.isinf(np.nan) False >>> np.isinf(np.NINF) True >>> np.isinf([np.inf, -np.inf, 1.0, np.nan]) array([ True, True, False, False], dtype=bool)
>>> x = np.array([-np.inf, 0., np.inf]) >>> y = np.array([2, 2, 2]) >>> np.isinf(x, y) array([1, 0, 1]) >>> y array([1, 0, 1])