input2.c

an introduction to boundary element methods一书源码

#include "cbox2.h"

void Input2(Xi,Yi,X,Y,Code,Bc)	
	
	float Xi[21],Yi[21],X[82],Y[82],Bc[161];
	int Code[161];
{
	FILE  *infile, *outfile;
	int   i,j,k,lnsize;
	char Title[80],line1[100]; 
	lnsize = 100;
		printf("\nNOTE: FIRST LINE IN THE INPUT FILE SHOULD BE EITHER BLANK OR THE TITLE NOT DATA \n"); 
		printf("\n Enter the name of the input file:");
        scanf("%s", inname);
        printf("\n Enter the name of the output file:");
        scanf("%s", outname);
       
        infile = fopen(inname, "r" );
        outfile = fopen(outname,"w" );
		
		fgets(line1,lnsize,infile);
		fprintf(outfile,"%s \n",line1);
		fprintf(outfile,"Input \n");
	
		fscanf(infile,"%d %d",&N,&L);
		
		fprintf(outfile," \nNumber of Boundary Elements = %d \n",N);

		fprintf(outfile," \nNumber of InteriorPoints = %d \n",L);

	
		fprintf(outfile," \nCoordinates of the Extreme Points");
		fprintf(outfile,"  of the  Boundary Elements  \n \n"); 

		fprintf(outfile,"Point      X          Y\n");

		for(i=1;i<=N;i++)
		{
			fscanf(infile,"%f %f",&X[i],&Y[i]);
			fprintf(outfile,"%2d   %10.4f %10.4f\n",i,X[i],Y[i]);
		}
		
/*[	Read boundary conditions in Bc[] vector. If Code[i] = 0, the Bc value is a known potential;  if Code[i] = 1, the Bc[] value is a known potential derivative (flux). Two Boundary conditions are read per element.  One node may have two values of the potential derivative but only one vlue of the potential ]*/


	fprintf(outfile," \nBoundary  Conditions \n\n");
	fprintf(outfile,"               First Node             Second Node\n");
	fprintf(outfile,"               Prescribed             Prescribed\n");
	fprintf(outfile,"Element     CODE   Value           CODE    Value\n");
	
	for(i=1;i<=N;i++)
	{
		fscanf(infile,"%d %f %d %f",&Code[2*i -1],&Bc[2*i -1],
					&Code[2*i],&Bc[2*i]);
					
		fprintf(outfile,"%2d\t\t\t%2d %10.4f\t\t\t%2d %10.4f\n",
				i,Code[2*i -1],Bc[2*i -1],Code[2*i],Bc[2*i]);
	}
	

/*[ Read coordinates of the interior points ]*/

	fprintf(outfile,"\nInterior Point Coordinates\n\n");
	fprintf(outfile,"       Xi         Yi\n");
	


		for(i=1;i<=L;i++)
		{
			fscanf(infile,"%f %f \n",&Xi[i],&Yi[i]);
			fprintf(outfile," %10.4f %10.4f\n",Xi[i],Yi[i]);
		}


	fclose(infile);
	fclose(outfile);
			
}