log2¶
- log2(x: array, /) array ¶
Calculates an implementation-dependent approximation to the base
2
logarithm for each elementx_i
of the input arrayx
.Note
For complex floating-point operands,
log2(conj(x))
must equalconj(log2(x))
.- Parameters:
x (array) – input array. Should have a floating-point data type.
- Returns:
out (array) – an array containing the evaluated base
2
logarithm for each element inx
. The returned array must have a floating-point data type determined by Type Promotion Rules.
Notes
Special cases
For real-valued floating-point operands,
If
x_i
isNaN
, the result isNaN
.If
x_i
is less than0
, the result isNaN
.If
x_i
is either+0
or-0
, the result is-infinity
.If
x_i
is1
, the result is+0
.If
x_i
is+infinity
, the result is+infinity
.
For complex floating-point operands, special cases must be handled as if the operation is implemented using the standard change of base formula
\[\log_{2} x = \frac{\log_{e} x}{\log_{e} 2}\]where \(\log_{e}\) is the natural logarithm, as implemented by
log()
.Changed in version 2022.12: Added complex data type support.