log() Mathematics Function log() Compute natural logarithm #include <math.h> double log(z) double z; log returns the natural (base e) logarithm of its argument z. ***** Example ***** For an example of this function, see the entry for exp. ***** See Also ***** log10(), mathematics library ***** Diagnostics ***** A domain error in log (z is less than or equal to zero) sets er- rno to EDOM and returns zero. COHERENT Lexicon Page 1