s17def

Purpose

Synopsis

[cy,nz,ifail] = s17def(fnu,z,n<,scale,ifail>)

Description

 
 This subroutine evaluates a sequence of values for the Bessel 
 function J    (z), where z is complex, -(pi) < arg z <= (pi), and
           (nu)                                                
 (nu) is the real, non-negative order. The N-member sequence is 
 generated for orders (nu), (nu)+1,...,(nu)+N-1. Optionally, the 
                                   -|Im z|
 sequence is scaled by the factor e       .
 
 Note: although the routine may not be called with (nu) less than 
 zero, for negative orders the formula 
 J     (z)=J    (z)cos((pi)(nu))-Y    (z)sin((pi)(nu)) may be used
  -(nu)     (nu)                  (nu)                        
 (for the Bessel function Y    (z), see S17DCF).
                           (nu)                
 
 For very large |z| or ((nu)+N-1), argument reduction will cause 
 total loss of accuracy, and so no computation is performed. For 
 slightly smaller |z| or ((nu)+N-1), the computation is performed 
 but results are accurate to less than half of machine precision. 
 If Im z is large, there is a risk of overflow and so no 
 computation is performed. In all the above cases, a warning is 
 given by the routine.
 

Parameters

s17def

Required Input Arguments:

fnu                                   real
z                                     complex
n                                     integer

Optional Input Arguments:                       <Default>

scale (1)                             string   'u'
ifail                                 integer  -1

Output Arguments:

cy (n)                                complex
nz                                    integer
ifail                                 integer