signbit

Syntax

signbit(X)

Details

Detects the sign bit of the input value.

Note:

DolphinDB signbit provides the same core functionality as numpy.signbit.The differences are as follows:

  • DolphinDB signbit is primarily intended for floating-point or integer scalars. For complex numbers, you can use lowDouble and highDouble to check the real and imaginary parts separately.
  • numpy.signbit supports element-wise computation on both scalars and arrays, and also supports additional parameters such as out, where。

Parameters

X is a floating-point or integer scalar.

Returns

true if X is negative, false otherwise.

Examples

$ signbit('a')
false

$ signbit(-21)
true

$ signbit(-2.1)
true

$ b=complex(10,-5)// create a complex number
$ b
10.0-5.0i
$ signbit(highDouble(b)) // detect the sign bit of the imaginary number
true
$ signbit(lowDouble(b))  // detect the sign bit of the real number
false