x=[-1:0.05:1];
y=[-1:0.05:1];
m=length(x);
n=length(y);
xc=zeros(m,n);
yc=zeros(m,n);
for i=1:m
for j=1:n
xc(j,i)=y(j);
yc(j,i)=((((-4*129944)/601)*x(i))-(((4*6000/601))*y(j)))/100;
end
end
figure (1);
plot(x,0*x,':k');
hold on % hold on here
plot(0*y,y,':k')
arrow=sqrt(xc.^2 + yc.^2);
% ./ instead of / for yc
quiver(x,y,xc./arrow,yc./arrow,0.5,'b')
xlim([min(x),max(x)])
ylim([min(y),max(y)])
%hold on
grid on
axis tight
