Re: Error in besselJ(pi/2, 1E-15)?

Mikael Jagan <[email protected]> Mon, 29 Dec 2025 16:10:24 -0500

Newsgroups	gmane.comp.lang.r.general
Message-ID	<[email protected]>

These lines (561-567) of src/nmath/bessel_j.c seem relevant. :-)


     L250:
     	    /* ---------------------------------------------------
     	       Normalize.  Divide all b[N] by sum.
     	       ---------------------------------------------------*/
     /*	    if (nu + 1. != 1.) poor test */
     	    if(fabs(nu) > 1e-15)
     		sum *= (Rf_gamma_cody(nu) * pow(.5* *x, -nu));


Mikael