External module "math/base/special/bessely1/docs/types/index.d"

Export assignment y1

• y1(x: number): number

• Computes the Bessel function of the second kind of order one.

  Notes

  • Accuracy for subnormal x is very poor. Full accuracy is achieved at 1.0e-308 but trends progressively to zero at 5e-324. This suggests that underflow (or overflow, perhaps due to a reciprocal) is effectively cutting off digits of precision until the computation loses all accuracy at 5e-324.

  Parameters

  • x: number

    input value

  Returns number

  evaluated Bessel function

  Example

  var v = y1( 0.0 );
  // returns -Infinity
  
  v = y1( 1.0 );
  // returns ~-0.781
  
  v = y1( -1.0 );
  // returns NaN
  
  v = y1( Infinity );
  // returns 0.0
  
  v = y1( -Infinity );
  // returns NaN
  
  v = y1( NaN );
  // returns NaN