signbit

signbit(x: array, /) → array

Determines whether the sign bit is set for each element x_i of the input array x.

The sign bit of a real-valued floating-point number x_i is set whenever x_i is either -0, less than zero, or a signed NaN (i.e., a NaN value whose sign bit is 1).

Parameters:

x (array) – input array. Should have a real-valued floating-point data type.

Returns:

out (array) – an array containing the evaluated result for each element in x. The returned array must have a data type of bool.

Notes

Special cases

For real-valued floating-point operands,

• If x_i is +0, the result is False.

• If x_i is -0, the result is True.

• If x_i is +infinity, the result is False.

• If x_i is -infinity, the result is True.

• If x_i is a positive (i.e., greater than 0) finite number, the result is False.

• If x_i is a negative (i.e., less than 0) finite number, the result is True.

• If x_i is NaN and the sign bit of x_i is 0, the result is False.

• If x_i is NaN and the sign bit of x_i is 1, the result is True.

New in version 2023.12.