Name

scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl
- compute exponent using FLT_RADIX

Library

libm.lib

Synopsis

  #include <math.h>
  double scalbln (double x, long n);
  float scalblnf (float x, long n);
  long double scalblnl (long double x, long n);
  double scalbn (double x, int n);
  float scalbnf (float x, int n);
  long double scalbnl (long double x, int n);

Return values

x (*, FLT_RADIX**n);

±HUGE_VAL, (±HUGE_VALF,, and, ±HUGE_VALL);
(according to the sign of x ) as appropriate for the return type of the function.

x is NaN , a shall be returned.

x is ±0 or ±Inf, x shall be returned.

n is 0, x shall be returned.

Detailed description

These routines return x *(2** n) computed by exponent manipulation.

Examples

#include <math.h>
int main( )
{  
   /*scalbn(), scalbnf() and scalbnl()*/
   double x1 = 0.8, x2 = 4.0 ;
   y = scalbn( x1, x2 );
   printf( "scalbn( %f, %f) = %f\n", x1, x2, y );
   y = scalbnf( x1, x2 );
   printf( "scalbnf( %f, %f) = %f\n", x1, x2, y );
   y = scalbnl( x1, x2 );
   printf( "scalbnl( %f, %f) = %f\n", x1, x2, y );
  /*scalbln(), scalblnf() and scalblnl()*/
   x1 = 0.8, x2 = 4.0 ;
   y = scalbln( x1, x2 );
   printf( "scalbln( %f, %f) = %f\n", x1, x2, y );
   y = scalblnf( x1, x2 );
   printf( "scalblnf( %f, %f) = %f\n", x1, x2, y );
   y = scalblnl( x1, x2 );
   printf( "scalblnl( %f, %f) = %f\n", x1, x2, y );
}

Output 

scalbn ( 0.8, 4.0 ) = 12.800000
scalbnf( 0.8, 4.0 ) = 12.800000
scalbnl( 0.8, 4.0 ) = 12.800000
scalbln ( 0.8, 4.0 ) = 12.800000
scalblnf( 0.8, 4.0 ) = 12.800000
scalblnl( 0.8, 4.0 ) = 12.800000

See also

ieee, math
These routines conform to -isoC-99, and they implement the Scalb function recommended by -ieee754.

Here long double version apis are just an alias to the corresponding double version apis, Long double version Apis behaves similiar to that of double version Apis.

The scalbn and scalbnf functions appeared in BSD 4.3 and 2.0 , respectively. The scalbln and scalblnf functions first appeared in 5.3 , and scalblnl and scalbln in 5.5 .

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