numpy.emath.log2#

emath.log2(x)[source]#

Compute the logarithm base 2 ofx.

Return the “principal value” (for a description of this, seenumpy.log2) of\(log_2(x)\). For realx > 0, this isa real number (log2(0) returns-inf andlog2(np.inf) returnsinf). Otherwise, the complex principle value is returned.

Parameters:
xarray_like

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

Returns:
outndarray or scalar

The log base 2 of thex value(s). Ifx was a scalar, so isout,otherwise an array is returned.

See also

numpy.log2

Notes

For a log2() that returnsNAN when realx < 0, usenumpy.log2(note, however, that otherwisenumpy.log2 and thislog2 areidentical, i.e., both return-inf forx = 0,inf forx = inf,and, notably, the complex principle value ifx.imag!=0).

Examples

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

>>>np.set_printoptions(precision=4)
>>>np.emath.log2(8)3.0>>>np.emath.log2([-4,-8,8])array([2.+4.5324j, 3.+4.5324j, 3.+0.j    ])
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