SUBROUTINE CURVl - Determines the necessary parameters to 

 compute an Interpol atory spline under 

 tension through a sequence of functional 

 values contained in arrays X2 and Y2 . 



FUNCTION CURV2 - Interpolates the given curve, Y2 as a 

 function of X2 , returning a value for 

 y given x . 



SUBROUTINE CURV3 - Determines the necessary parameters to 

 compute an interpolatory spline under 

 tension through a sequence of functional 

 values contained in arrays X2P and Y2P. 



FUNCTION CURV4 - Interpolates the given curve, Y2P as a 

 function of X2P , returning a value for 

 y given x . 



3. Type of Computer. 



The program GRID may be run on any computer with minimum 

 core requirements of approximately 26K words (based on the 

 present sample program appropriate to the Hurricane Carla 

 surge simulation grid) . GRID requires no auxiliary storage 

 devices, peripheral devices, or magnetic tape input or output. 

 No site-oriented computer plot routines are involved in the 

 program. Approximately 25 minutes of machine time on a 

 GE/635 is required for the sample program to determine the 

 computing grid information. This time is based on the 

 following pertinent program parameters: 



a) 150 transformation coefficients, B or C j 



n n 



b) 121 evenly spaced values of 5 for determining the 

 trans form- generated coastline arclength as a function 

 of K ; 



c) 51 evenly spaced values of n for determining the arc- 

 length along a particular isoline of C as a function 

 of n ; 



d) the computing grid of 47 E, (or S*) lines and 15 n (or 

 T*) lines; 



e) for determining the scale factor F , the area in x,y 

 space of each quadrangle is approximated by using 4 

 evenly spaced increments between ^ isolines and 2 

 evenly spaced increments between n isolines . 



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