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log2

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< c | numeric | math
 
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Defined in header <math.h>
float       log2f( float arg );
 (since C99)
double      log2( double arg );
 (since C99)
long double log2l( long double arg );
 (since C99)

Computes the base 2 logarithm of arg.

[edit] Parameters

arg - floating point value

[edit] Return value

log
2(arg)

Domain error occurs if arg is negative. NAN is returned in that case.

Range error occurs if arg is ​0​. -HUGE_VAL is returned in that case.

[edit] See also

 computes natural (base e) logarithm (to base e) (ln(x))
(function) [edit]
computes common (base 10) logarithm (log10(x))
(function) [edit]
C++ documentation for log2
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