APPEKDIX C 

 Computer Program to Produce Matrices for Deriving 

 Equations of Linear Siirfaces 

 PROGRAM TITLE : PRMA.T, 

 Variables Used ib Program ; 



(x(l),I=l^ U) . . The X co-ordinates of the four data points. 

 (y(i),I=1; U) . . The Y co-ordinates of the four data points. 



S^M Matrices used in determiningcthe coefficients for an equation 



of a linear surface of best-fit to data values at fotir points. 

 Summary of Program : 



Let C represent wave velocity at any grid position X^Y. By specifying the 

 X,Y values for four positions, this program outputs S and M. When later 

 manipulated with a particular set of C values for these same four positions, 

 S and M produce the coefficients (E's) of linear equation of the form, 

 C = E-| + EpX + E„Y. This equation represents the least-squares plane of 

 best-fit to this particular set of C values. 

 Remarks : 



This program was extracted from a general program provided by W. C. Krumbein 

 that fits a first, second, or third-order polynomial surface to specified 

 regularly- spaced data points by the least-squares method. 

 The output from this program serves as input to MAIN 162O and MAIM 709U 

 (Appendices D and E) . 



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