C/math.h/log2
log2: returns the base 2 logarithm for num
<source lang="cpp">
//Declaration: float log2f(float num);
double log2(double num); long double log2l(long double num); #include <math.h> #include <stdio.h> int main(void) { double val = 1.0; do { printf("%f %f\n", val, log2(val)); val++; } while (val<11.0); return 0; }
/* 1.000000 0.000000 2.000000 1.000000 3.000000 1.584963 4.000000 2.000000 5.000000 2.321928 6.000000 2.584963 7.000000 2.807355 8.000000 3.000000 9.000000 3.169925 10.000000 3.321928
- /
</source>