- numpy.log10(x[, out]) = <ufunc 'log10'>¶
Return the base 10 logarithm of the input array, element-wise.
x : array_like
y : ndarray
The logarithm to the base 10 of x, element-wise. NaNs are returned where x is negative.
Logarithm is a multivalued function: for each x there is an infinite number of z such that 10**z = x. The convention is to return the z 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 yields nan and sets the invalid floating point error flag.
For complex-valued input, log10 is a complex analytical function that has a branch cut [-inf, 0] and is continuous from above on it. log10 handles the floating-point negative zero as an infinitesimal negative number, conforming to the C99 standard.
[R44] M. Abramowitz and I.A. Stegun, “Handbook of Mathematical Functions”, 10th printing, 1964, pp. 67. http://www.math.sfu.ca/~cbm/aands/ [R45] Wikipedia, “Logarithm”. http://en.wikipedia.org/wiki/Logarithm
>>> np.log10([1e-15, -3.]) array([-15., NaN])