| /*************************************************************************/ |
| /* */ |
| /* Copyright (c) 1994 Stanford University */ |
| /* */ |
| /* All rights reserved. */ |
| /* */ |
| /* Permission is given to use, copy, and modify this software for any */ |
| /* non-commercial purpose as long as this copyright notice is not */ |
| /* removed. All other uses, including redistribution in whole or in */ |
| /* part, are forbidden without prior written permission. */ |
| /* */ |
| /* This software is provided with absolutely no warranty and no */ |
| /* support. */ |
| /* */ |
| /*************************************************************************/ |
| |
| /* ************************************************************** |
| end of subroutine jacobcalc |
| ************************************************************** |
| |
| performs the laplacian calculation for a subblock. */ |
| |
| #include <stdio.h> |
| #include <math.h> |
| #include <time.h> |
| #include "decs.h" |
| |
| void laplacalc(x,z,firstrow,lastrow,firstcol,lastcol,numrows,numcols) |
| |
| double x[IMAX][JMAX]; |
| double z[IMAX][JMAX]; |
| int firstrow,lastrow,firstcol,lastcol,numrows,numcols; |
| |
| { |
| int iindex; |
| int indexp1; |
| int indexm1; |
| int ip1; |
| int im1; |
| int i; |
| int j; |
| |
| for (iindex=firstcol;iindex<=lastcol;iindex++) { |
| indexp1 = iindex+1; |
| indexm1 = iindex-1; |
| for (i=firstrow;i<=lastrow;i++) { |
| ip1 = i+1; |
| im1 = i-1; |
| z[i][iindex] = factlap*(x[ip1][iindex]+x[im1][iindex]+x[i][indexp1]+ |
| x[i][indexm1]-4.*x[i][iindex]); |
| } |
| } |
| if (firstrow == 1) { |
| for (j=firstcol;j<=lastcol;j++) { |
| z[0][j] = 0.0; |
| } |
| } |
| if ((firstrow+numrows) == im-1) { |
| for (j=firstcol;j<=lastcol;j++) { |
| z[im-1][j] = 0.0; |
| } |
| } |
| if (firstcol == 1) { |
| for (j=firstrow;j<=lastrow;j++) { |
| z[j][0] = 0.0; |
| } |
| } |
| if ((firstcol+numcols) == jm-1) { |
| for (j=firstrow;j<=lastrow;j++) { |
| z[j][jm-1] = 0.0; |
| } |
| } |
| } |
