_y0, _y1, _yn (Windows CE 5.0)

Artikel
09/14/2012

Developing an Application > Microsoft C Run-time Library for Windows CE > Run-time Library Reference

Compute the Bessel function.

double _y0( double x );double _y1( double x );double _yn( int n, double x );

Parameters

x
Floating-point value.
n
Integer order of Bessel function.

Return Values

Each of these routines returns a Bessel function of x. If x is negative, the routine prints a _DOMAIN error message to stderr, and returns _HUGE_VAL. You can modify error handling by using _matherr.

Remarks

These functions are supported by all versions of the C run-time libraries.

The _y0, _y1, and _yn routines return Bessel functions of the second kind: orders 0, 1, and n, respectively.

Example

Description

This program illustrates Bessel functions, including: _j0 _j1 _jn _y0 _y1 _yn

Code

void main( void )
{
   double x = 2.387;
   int n = 3, c;

   printf( "Bessel functions for x = %f:\n", x );
   printf( " Kind\t\tOrder\tFunction\tResult\n\n" );
   printf( " First\t\t0\t_j0( x )\t%f\n", _j0( x ) );
   printf( " First\t\t1\t_j1( x )\t%f\n", _j1( x ) );
   for( c = 2; c < 5; c++ )
      printf( " First\t\t%d\t_jn( n, x )\t%f\n", c, _jn( c, x ) );
   printf( " Second\t0\t_y0( x )\t%f\n", _y0( x ) );
   printf( " Second\t1\t_y1( x )\t%f\n", _y1( x ) );
   for( c = 2; c < 5; c++ )
      printf( " Second\t%d\t_yn( n, x )\t%f\n", c, _yn( c, x ) );
}
// Output
Bessel functions for x = 2.387000:
  Kind      Order   Function   Result

  First      0   _j0( x )   0.009288
  First      1   _j1( x )   0.522941
  First      2   _jn( n, x )   0.428870
  First      3   _jn( n, x )   0.195734
  First      4   _jn( n, x )   0.063131
  Second   0   _y0( x )   0.511681
  Second   1   _y1( x )   0.094374
  Second   2   _yn( n, x )   -0.432608
  Second   3   _yn( n, x )   -0.819314
  Second   4   _yn( n, x )   -1.626833

Requirements

OS Versions: Windows CE 2.0 and later.

Header: stdlib.h.

Link Library: coredll.dll.

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