numpy.log10¶

numpy.log10(x,/,out=None,*,where=True,casting='same_kind',order='K',dtype=None,subok=True[,signature,extobj]) = <ufunc 'log10'>¶

Return the base 10 logarithm of the input array, element-wise.

Parameters:

x:array_like Input values. out:ndarray, None, or tuple of ndarray and None, optional A location into which the result is stored. If provided, it must havea shape that the inputs broadcast to. If not provided orNone,a freshly-allocated array is returned. A tuple (possible only as akeyword argument) must have length equal to the number of outputs. where:array_like, optional Values of True indicate to calculate the ufunc at that position, valuesof False indicate to leave the value in the output alone. **kwargs For other keyword-only arguments, see theufunc docs.

Returns:

y:ndarray The logarithm to the base 10 ofx, element-wise. NaNs arereturned where x is negative.This is a scalar ifx is a scalar.

See also

emath.log10

Notes

Logarithm is a multivalued function: for eachx there is an infinitenumber ofz such that10**z = x. The convention is to return thez whose imaginary part lies in[-pi, pi].

For real-valued input data types,log10 always returns real output.For each value that cannot be expressed as a real number or infinity,it yieldsnan and sets theinvalid floating point error flag.

For complex-valued input,log10 is a complex analytical function thathas a branch cut[-inf, 0] and is continuous from above on it.log10 handles the floating-point negative zero as an infinitesimalnegative number, conforming to the C99 standard.

References

[1]	M. Abramowitz and I.A. Stegun, “Handbook of Mathematical Functions”,10th printing, 1964, pp. 67.http://www.math.sfu.ca/~cbm/aands/

[2]	Wikipedia, “Logarithm”.https://en.wikipedia.org/wiki/Logarithm

Examples

>>>np.log10([1e-15,-3.])array([-15.,  NaN])