why i am not getting the plot while giving the following program with if else statyement?please help

r=10; d=[1 100 1000]; P1=10^9; P2=130*10^9; s=d./r;

a=0; c=2; x=s; if (a<=x<=2); e1=1; else if (x>=2); e1=((d./r)+2)./4; else if (x>2); e1=(d./r)./4; end end end

u=e1.*P1; ug=e1.*P2; plot(d,u,'green') hold; plot(d,ug ,'red');

Answer 1

[Chandrasekhar]

r=10; d=[1 100 1000]; P1=10^9; P2=130*10^9; s=d./r;

a=0; c=2; x=s;
if (a<=x<=2)
    e1=1; 
else if (x>=2)
        e1=((d./r)+2)./4; 
    else if (x>2)
            e1=(d./r)./4; 
        end
    end
end

u=e1.*P1; 
ug=e1.*P2; 
plot(d,u,'green')
hold; 
plot(d,ug ,'red');

[an]

still it is not showing any plots.its coming like dots only

[Chandrasekhar]

yes, thats because d and u are scalars. they should be vectors if you want to represent in the form of a graph