+++ /dev/null
-/*
-The code below for calculating the voltage at a point i,j, given the
-voltages and permittivities at the four adjacent points (i,j+1),
-(i,j-1), (i-1,j), and (i+1,j), although I am not convinced it is
-100% correct in the case of mulitple dielectrics, the errors are
-still very small.
-*/
-
-
-#include "config.h"
-
-#ifdef HAVE_STDLIB_H
-#include <stdlib.h>
-#endif
-
-#ifdef HAVE_STDIO_H
-#include <stdio.h>
-#endif
-
-#include "definitions.h"
-
-
-extern int width, height;
-extern double **Er;
-extern unsigned char **oddity;
-extern int dielectrics_to_consider_just_now;
-extern double r;
-extern int coupler;
-
-#include "exit_codes.h"
-
-/* The following function updates the voltage on the matrix V_to given data about the
-oddity of the location i,j and the voltages in the matrix V_from. It does this for n interations
-between rows jmin and jmax inclusive and between columns imain and imax inclusive */
-
-void update_voltage_array(int nmax, int imin, int imax, int jmin, int jmax, double **V_from, double **V_to)
-{
- int k, i, j, n;
- unsigned char oddity_value;
- double Va, Vb, Vl, Vr, ERa, ERb, ERl, ERr;
- double Vnew, g;
-
- if (dielectrics_to_consider_just_now==1)
- g=r;
- else
- g=1;
- for(n=0; n < nmax; ++n)
- for(k=0; k < 4; ++k)
- for (i = k&1 ? imax : imin; k&1 ? i >=imin : i <= imax ; k&1 ? i-- : i++)
- for (j = (k==0 || k ==3) ? jmin : jmax; (k ==0 || k == 3) ? j <= jmax : j >= jmin ; (k == 0 || k ==3) ? j++ : j--){
- oddity_value=oddity[i][j];
-
- if( oddity_value == CONDUCTOR_ZERO_V ){
- V_to[i][j]=0.0;
- }
-
- else if( oddity_value == CONDUCTOR_PLUS_ONE_V ){
- V_to[i][j]=1.0;
- }
-
- else if( oddity_value == CONDUCTOR_MINUS_ONE_V ){
- V_to[i][j]=-1.0;
- }
-
- else if( oddity_value == TOP_LEFT_CORNER ) { /* top left */
- Vnew=0.5*(V_from[1][0]+V_from[0][1]);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
- else if( oddity_value == TOP_RIGHT_CORNER ) {
- Vnew=0.5*(V_from[width-2][0]+V_from[width-1][1]); /* top right */
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if(oddity_value == BOTTOM_LEFT_CORNER) {
- Vnew=0.5*(V_from[0][height-2]+V_from[1][height-1]); /* bottom left */
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == BOTTOM_RIGHT_CORNER) {
- Vnew=0.5*(V_from[width-2][height-1]+V_from[width-1][height-2]); /* bottom right */
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- /* Now the sides */
-
- else if( oddity_value == ORDINARY_POINT_LEFT_EDGE ){ /* left hand side */
- Vnew=0.25*(V_from[0][j-1]+V_from[0][j+1] + 2*V_from[1][j]);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == ORDINARY_POINT_RIGHT_EDGE){ /* right hand side */
- Vnew=0.25*(V_from[width-1][j+1]+V_from[width-1][j-1]+2*V_from[width-2][j]);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == ORDINARY_POINT_TOP_EDGE ){ /* top row */
- Vnew=0.25*(V_from[i-1][0]+V_from[i+1][0]+2*V_from[i][1]);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == ORDINARY_POINT_BOTTOM_EDGE ){ /* bottom row */
- Vnew=0.25*(V_from[i-1][height-1]+V_from[i+1][height-1]+2*V_from[i][height-2]);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if ( oddity_value == ORDINARY_INTERIOR_POINT || (oddity_value>=DIFFERENT_DIELECTRIC_ABOVE_AND_RIGHT && oddity_value < UNDEFINED_ODDITY && dielectrics_to_consider_just_now == 1) ) {
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=(Va+Vb+Vl+Vr)/4.0;
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- /* I'm not sure the following equations, which compute the voltage
- where there is a metal around are okay. One line of thought would
- say that the same equations as normal i.e.
- v_new=(v(i+1,j_+v(i-1,j)+v(i,j-1)+v(i,j+1))/4 should be used
- but then since the electric field across the metal surface is zero,
- the equation that was used to derrive that equation is not valid.
-
- Another thought of mine is that voltage near a metal will be more affected
- by the metal than the dielectric, since the nearest part of the metal is at
- at the same voltage as the node, whereas for a dielectric is less so. Hence
- the following seems a sensible solution. Since the metal will have twice
- the effect of a dielectric, the voltage at i,j should be weighted such
- that its effect is more strongly affected by the metal. This seems to
- produce reasonably accurate results, but whether this is chance or not
- I don't know. */
-
- else if( oddity_value == METAL_ABOVE ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Va/3+2*Vb/3+Vl+Vr);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == METAL_BELOW ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Vb/3+2*Va/3+Vl+Vr);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == METAL_LEFT ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Vl/3+2*Vr/3+Va+Vb);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == METAL_RIGHT ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Vr/3+2*Vl/3+Va+Vb);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == METAL_ABOVE_AND_RIGHT ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Vr/3+4*Va/3 +2*Vl/3 + 2*Vb/3);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == METAL_ABOVE_AND_LEFT ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Vl/3+4*Va/3+2*Vr/3+2*Vb/3);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == METAL_BELOW_AND_LEFT ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Vl/3+4*Vb/3+2*Vr/3+2*Va/3);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- else if( oddity_value == METAL_BELOW_AND_RIGHT ){
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- Vnew=0.25*(4*Vb/3+4*Vr/3+2*Va/3+2*Vl/3);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
- }
-
- /* Again, when there is a change of permittivity, my equations may
- (probably are wrong). My logic is that if there's and RF field,
- the impedance is inversly proportional to Er. So if the material
- above a node is of a higher permittivity, then the
- voltage will be closer to that of the node above, becuase of this.
- The same applies for other directions of change in Er. */
-
-
- else if(dielectrics_to_consider_just_now > 1){
-
- Va=V_from[i][j-1];
- Vb=V_from[i][j+1];
- Vl=V_from[i-1][j];
- Vr=V_from[i+1][j];
-
- ERa=Er[i][j-1];
- ERb=Er[i][j+1];
- ERl=Er[i-1][j];
- ERr=Er[i+1][j];
-
- Vnew=(Va * ERa + Vb * ERb + Vl * ERl + Vr * ERr)/(ERa + ERb + ERl + ERr);
- V_to[i][j]=g*Vnew+(1-g)*V_from[i][j];
-
- }
- else if ( (dielectrics_to_consider_just_now == 1 && oddity_value == UNDEFINED_ODDITY) || (dielectrics_to_consider_just_now > 1)) {
- fprintf(stderr,"Internal error in update_voltage_array.c\n");
- fprintf(stderr,"i=%d j=%d oddity[%d][%d]=%d\n",i,j,i,j,oddity[i][j]);
- exit(INTERNAL_ERROR);
- } /* end if if an internal error */
-
- } /* end of j loop */
-}
projects / debian / atlc / blobdiff