clear all Q1=5e-12; Q2=-5e-12; e0=8.854e-12; k=1/(4*pi*e0); r1=[1, 2]*1e-2; r2=[2,3]*1e-2; dx=0.5e-3;dy=0.5e-3; maxx=4e-2;maxy=4e-2; x=0:dx:maxx; y=0:dy:maxy; [X,Y]=meshgrid(0:dx:maxx,0:dy:maxy); for i=1:1:length(x) for j=1:1:length(y) p1x=r1(1,1)-x(i); p1y=r1(1,2)-y(j); psqr=sqrt(p1x^2+p1y^2); if psqr==0 psqr=1e-10; end E1x(i,j)=k*Q1*p1x/psqr^3; E1y(i,j)=k*Q1*p1y/psqr^3; end end Eabs=(sqrt(E1x.^2+E1y.^2)); Emax=max(max(Eabs)); [i,j]=find(Eabs==0); Eabs(i,j)=Emax; figure,mesh(Eabs) figure,contour(X,Y,Eabs) %E=ERP1 + ERP2 %for i=1:len % Eabs(i)=sqrt(E(i,1)^2+E(i,2)^2+E(i,3)^2); %end