6.6 Modified Bessel Functions of Integer Order 237 3 Permission is 2 1K0 K 、K2 h 2 http://ww.nr.com or call 1-800-872-7423 (North America 0 0 2 3 Figure 6.6.1. Modified Bessel functions lo(x)through Is(x),Ko(x)through K2(x). only),or readable files (including this one)to any server computer,is strictly prohibited. #include <math.h> float bessio(float Returns the modified Bessel function lo(x)for any real x. float ax,ans; double yi Accumulate polynomials in double precision. Copyright(C)1988-1992 by Cambridge University Press.Programs Copyright(C)1988-1992 by Numerical Recipes Sample page from NUMERICAL RECIPES IN C:THE ART OF SCIENTIFIC COMPUTING(ISBN 0-521-43108-5) if ((ax=fabs(x)<3.75) Polynomial fit y=x/3.75; y*=y; ans=1.0+y*(3.5156229+y*(3.0899424+y*(1.2067492 +y*(0.2659732+y*(0.360768e-1+y*0.45813e-2)))) else y=3.75/ax; ans=(exp(ax)/sqrt(ax))*(0.39894228+y*(0.1328592e-1 +y*(0.225319a-2+y*(-0.157565e-2+y*(0.916281e-2 +y*(-0.2057706e-1+y*(0.2635537e-1+y*(-0.1647633e-1 +y*0.392377e-2))))); rsend email to directcustserv@cambridge.org(outside North America) Software. return ans; ying of machine #include <math.h> float bessk0(float x) Returns the modified Bessel function Ko(x)for positive real x. float bessio(float x); double y,ans; Accumulate polynomials in double precision.6.6 Modified Bessel Functions of Integer Order 237 Permission is granted for internet users to make one paper copy for their own personal use. Further reproduction, or any copyin Copyright (C) 1988-1992 by Cambridge University Press. Programs Copyright (C) 1988-1992 by Numerical Recipes Software. Sample page from NUMERICAL RECIPES IN C: THE ART OF SCIENTIFIC COMPUTING (ISBN 0-521-43108-5) g of machine￾readable files (including this one) to any server computer, is strictly prohibited. To order Numerical Recipes books or CDROMs, visit website http://www.nr.com or call 1-800-872-7423 (North America only), or send email to directcustserv@cambridge.org (outside North America). 0 1 2 3 4 01234 modified Bessel functions x K0 K1 K2 I0 I1 I2 I3 Figure 6.6.1. Modified Bessel functions I0(x) through I3(x), K0(x) through K2(x). #include <math.h> float bessi0(float x) Returns the modified Bessel function I0(x) for any real x. { float ax,ans; double y; Accumulate polynomials in double precision. if ((ax=fabs(x)) < 3.75) { Polynomial fit. y=x/3.75; y*=y; ans=1.0+y*(3.5156229+y*(3.0899424+y*(1.2067492 +y*(0.2659732+y*(0.360768e-1+y*0.45813e-2))))); } else { y=3.75/ax; ans=(exp(ax)/sqrt(ax))*(0.39894228+y*(0.1328592e-1 +y*(0.225319e-2+y*(-0.157565e-2+y*(0.916281e-2 +y*(-0.2057706e-1+y*(0.2635537e-1+y*(-0.1647633e-1 +y*0.392377e-2)))))))); } return ans; } #include <math.h> float bessk0(float x) Returns the modified Bessel function K0(x) for positive real x. { float bessi0(float x); double y,ans; Accumulate polynomials in double precision