# plotting lines

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Muhammad Usman on 11 Dec 2011
i have a simple ques that if i have z-plane having x and y axes,and i express z=x+i*y,and x if fixed let say 5 any y=0:10 then how can i plot this thing,please guide me,i m waiting for reply
Muhammad Usman on 12 Dec 2011
yes i is imaginaryunit

bym on 11 Dec 2011
y = 1:10;
x=5*ones(size(y));
z=x+i*y;
plot(real(z),imag(z))
Walter Roberson on 11 Dec 2011
That will not be able to show the values of x and y on the axes.

Mohsen Davarynejad on 11 Dec 2011
y = [0:.1:10]
plot(5,y)
xlabel('Re')
ylabel('Im')
Walter Roberson on 12 Dec 2011
z might be a line in the complex plane, but plot(5,y) does not involve z at all, and plot(5,z) would be refused because it is not allowed to plot complex data except through plot(z) which in turn is the same as plot(real(z),imag(z)) -- real vs imaginary.

Walter Roberson on 11 Dec 2011
y = 0:10;
x = 5 * ones(size(y));
z = x + i * y;
Now, if "i" were a real-valued constant, you would then use
plot3(x, y, z)
However, "i" is the complex constant, so you have a line in complex space, and there is no way to draw that in one step. Instead you would need to use something like,
plot3(x, y, real(z), 'r', x, y, imag(z), 'g', x, y, abs(z), 'b')
or perhaps plot 3 separate images using subplot()
Muhammad Usman on 12 Dec 2011
i just tried your code where "i" is complex constant...now i want to ask that how can a draw a rectangle shape and color it on the axes,i.e.let x=0:5 and y=0:7 and these lines meet at(5,7),so guide me.