`numpy.lib.scimath:log2`

source: build-install/usr/lib/python3.14/site-packages/numpy/lib/_scimath_impl.py :385

Signature

def log2 ( x )

Summary

Compute the logarithm base 2 of x.

Extended Summary

Return the "principal value" (for a description of this, see numpy.log2) of $l o g_{2} (x)$ . For real x > 0, this is a real number (log2(0) returns -inf and log2(np.inf) returns inf). Otherwise, the complex principle value is returned.

Parameters

x : array_like: The value(s) whose log base 2 is (are) required.

Returns

out : ndarray or scalar: The log base 2 of the x value(s). If x was a scalar, so is out, otherwise an array is returned.

Notes

For a log2() that returns NAN when real x < 0, use numpy.log2 (note, however, that otherwise numpy.log2 and this log2 are identical, i.e., both return -inf for x = 0, inf for x = inf, and, notably, the complex principle value if x.imag != 0).

Examples

We set the printing precision so the example can be auto-tested:

np.set_printoptions(precision=4)

✓

np.emath.log2(8)

✗

np.emath.log2([-4, -8, 8])

✓

Aliases

numpy.emath.log2