J0(3) BSD Programmer's Manual J0(3) NNAAMMEE jj00, jj11, jjnn, yy00, yy11, yynn - bessel functions of first and second kind SSYYNNOOPPSSIISS ##iinncclluuddee <<mmaatthh..hh>> _d_o_u_b_l_e jj00(_d_o_u_b_l_e _x); _d_o_u_b_l_e jj11(_d_o_u_b_l_e _x); _d_o_u_b_l_e jjnn(_i_n_t _n, _d_o_u_b_l_e _x); _d_o_u_b_l_e yy00(_d_o_u_b_l_e _x); _d_o_u_b_l_e yy11(_d_o_u_b_l_e _x); _d_o_u_b_l_e yynn(_i_n_t _n, _d_o_u_b_l_e _x); DDEESSCCRRIIPPTTIIOONN The functions jj00() and jj11() compute the _B_e_s_s_e_l _f_u_n_c_t_i_o_n _o_f _t_h_e _f_i_r_s_t _k_i_n_d _o_f _t_h_e _o_r_d_e_r 0 and the _o_r_d_e_r 1, respectively, for the real value _x; the function jjnn() computes the _B_e_s_s_e_l _f_u_n_c_t_i_o_n _o_f _t_h_e _f_i_r_s_t _k_i_n_d _o_f _t_h_e _i_n_t_e_g_e_r Bessel0 _n for the real value _x. The functions yy00() and yy11() compute the linearly independent _B_e_s_s_e_l _f_u_n_c_t_i_o_n _o_f _t_h_e _s_e_c_o_n_d _k_i_n_d _o_f _t_h_e _o_r_d_e_r 0 and the _o_r_d_e_r 1, respectively, for the postive _i_n_t_e_g_e_r value _x (expressed as a double); the function yynn() computes the _B_e_s_s_e_l _f_u_n_c_t_i_o_n _o_f _t_h_e _s_e_c_o_n_d _k_i_n_d _f_o_r _t_h_e _i_n_t_e_g_e_r Bessel0 _n for the postive _i_n_t_e_g_e_r value _x (expressed as a double). RREETTUURRNN VVAALLUUEESS If these functions are successful, the computed value is returned. On the VAX and Tahoe architectures, a negative _x value results in an error; the global variable _e_r_r_n_o is set to EDOM and a reserve operand fault is gen- erated. SSEEEE AALLSSOO math(3), infnan(3) HHIISSTTOORRYY A set of these functions function appeared in Version 7 AT&T UNIX. 4th Berkeley Distribution June 4, 1993 1