xj2070 发表于 2005-8-28 16:56

about hankel function

<P>1由于国内常见的fortran程序集合中没有直接关于hankel 函数的,且IMSL 函数中也只有<BR>bessel 函数,希望下面的小程序对大家有一点帮助。<BR>2。是基于bessel 的IMSL 函数的<BR><BR>3。subroutine hankel(order,class,x,res)<BR> <BR> !Function: Compute the hankel function values <BR> !   <BR> !Note:<BR> !<BR> !This is a very useful subroutine,for that in IMSL<BR> !the hankel function is not provided directly.<BR> !The bessel function in IMsl LIBARY is not very good<BR> !when CLASS=3 WHICH REPRENTS THE FIRSTKIND BESSEL FUNCTION<BR> !when class=4 WHICH REPRENTS THE second KIND BESSEL FUNCTION <BR> !<BR> ! Input:<BR> !    <BR> !      order-------- the order number describing the hankel's function<BR> !      class-------- the hankel fuction's classfication <BR> !      x    ---------thevariable (real)   <BR> !<BR> ! Output:<BR> !      res --------- the results (complex)<BR> !<BR> !         <BR>      <BR>       ImplicitNone<BR>    <BR>    Integer order,N      !the order number requried for computation <BR>    Integer class      !the kind number<BR>    <BR>    Realx,CBS1(order+1),CBS2(order+1) !argument x                <BR>       complexres,i </P>
<P>!--------------------------------------------------------------------</P>
<P>    i=(0,1)      ! the false root<BR>    N=order+1         ! in order compute the order-th results</P>
<P>    Call BSJNS(x,N,CBS1)<BR>    Call BSYS(0.0,x,N,CBS2)</P>
<P>!--------------------------------------------------------------------</P>
<P>       If(class==1)Then</P>
<P>   res=CBS1(N)+i*(CBS2(N))   !the first kind hankel function<BR>       <BR>    Else if(class==2) then<BR>         <BR>    res=CBS1(N)-i*(CBS2(N)) !the second kind hankel function<BR>    <BR>    Else if(class==3) then!the REPRENTS THE FIRSTKIND BESSEL FUNCTION<BR>      <BR>    res=CBS1(N)+i*0.0</P>
<P>    Else if(class==4) then! the REPRENTS THE Second KIND BESSEL FUNCTION<BR>      <BR>    res=CBS2(N)+i*0.0<BR>   <BR>Else<BR>            <BR>   write(*,*) 'the order num is illegal'<BR><BR>   stop <BR>   <BR>    End if<BR> <BR> End subroutine </P>

christy 发表于 2005-8-28 20:16

回复:(xj2070)about hankel function

<P>谢谢搂主,希望搂住以后能提供更多的好东西</P>
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