ERF(3) BSD Programmer's Manual ERF(3) NNAAMMEE eerrff, eerrffcc - error function operators SSYYNNOOPPSSIISS ##iinncclluuddee <<mmaatthh..hh>> _d_o_u_b_l_e eerrff(_d_o_u_b_l_e _x); _d_o_u_b_l_e eerrffcc(_d_o_u_b_l_e _x); DDEESSCCRRIIPPTTIIOONN These functions calculate the error function of _x. The eerrff() calculates the error function of x; where erf(x) = 2/sqrt(pi)*integral from 0 to x of exp(-t*t) dt. The eerrffcc() function calculates the complementary error function of _x; that is eerrffcc() subtracts the result of the error function eerrff(_x) from 1.0. This is useful, since for large _x places disappear. SSEEEE AALLSSOO math(3) HHIISSTTOORRYY The eerrff() and eerrffcc() functions appeared in 4.3BSD. 4.3 Berkeley Distribution June 4, 1993 1