APPENDIX A: NORMAL MODE PROGRAM IN FORTRAN 



This program consists of the main program and seven subroutines. The main pro- 

 gram handles the input and output and performs much of the computation. This includes 

 profile preparation, mode search, determination of depth function coefficients, normaliza- 

 tion, computation of depth functions, and summation of modes. Auxiliary functions are 

 performed by the subroutines SETUP and DET, which set up the determinant, then evaluate 

 it. This is the determinant from which eigenvalues are determined. The subroutine HZERO 

 determines the Hankel functions of order zero, second type, which gives the range depend- 

 ence of the modes. Only a single term of the asymptotic expansion is needed for this 

 function. 



Subroutine HANKEL evaluates the modified Hankel functions of order 1/3, by 

 which the depth dependence of the modes is expressed. The majority of computing time is 

 usually expended in this subroutine. Subroutine CFR is used by subroutine HANKEL to 

 evaluate continued fractions. Subroutine RCOEF evaluates and prints reflection coeffi- 

 cients when they are requested. 



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