II. COMPUTER PROGRAM DOCUMENTATION FOR PROGRAM-CONFORM 



1 . Program Purpose . 



The purpose of the program is to determine the transformation 

 coefficients which will conformally map the interior region bounded 

 by the actual coastline, a seaward boundary curve, and two parallel 

 lateral boundaries into a rectangle in the image plane. 



2. Program Description. 



The program is written in FORTRAN IV language. This program and 

 the program GRID provide all the necessary computing grid data for 

 input to program SSURGE. The program GRID takes, as input, the 

 transformation coefficients and determines the computing grid infor- 

 mation (such as, scale factors, grid point locations, and, at each 

 grid point, the orientation of the ^-axis to the x-axis) . 



The program CONFORM is composed of: 



MAIN 



Defines constants. Reads and writes the 

 coordinates delineating the given coastline 

 and seaward boundary curve. Calls Subroutine 

 COEFFS. 



SUBROUTINE COEFFS 



FUNCTION XTRAN 

 FUNCTION YTRAN 

 SUBROUTINE SLFAC 



Determines the transformation coefficients. 

 At the completion of each iteration, the 

 coefficients, the variance between the 

 transform-generated curves and that speci- 

 fied, and other pertinent information are 

 written. COEFFS interfaces ail other 

 program subroutines and functions. 



Is the transformation function x(C,n) • 



Is the transformation function y(5.il) - 



Determines the scale factor and derivatives, 

 3x/9C , 3y/35 , for a given value of 5 and 



SUBROUTINE CURIYB 



FUNCTION CURVYB 



Determines the necessary parameters to fit a 

 spline under tension through the given coast- 

 line coordinates. The spline is fitted with 

 Y2 as a function of X2 . 



Interpolates the given coastline , returning 

 a value of y at a specified value for x , 



