# Can someone tell me why my graph isn't plotting?

3 views (last 30 days)
Kane Patrick Bobier on 23 Oct 2020
Commented: Star Strider on 23 Oct 2020
I am trying to plot Coefficient of Drag (Cd) and Coefficient of Lift (Cl) vs. Angle of Attack (a). The code doesn't have any errors but nothing is boing plotted. My for loop produces the Cd and Cl values that I need. Can someone check my code?
%area
A = 0.152 * 0.3;
a = 0:5:50;
Pd = [
0.65,
0.65,
0.64,
0.59,
0.55,
0.53,
0.49,
0.43,
0.38,
0.33,
0.26
];
Fl = [
-17.23,
-4.6,
6.25,
13.37,
12.54,
13.82,
17.24,
19.51,
21.88,
22.83,
19.56
];
Fd = [
5.07,
5.41,
6.79,
10.23,
12.42,
16.46,
19.69,
23.38,
27.1,
30.02,
3.35
];
for i = 1:numel(Pd)
Cl = (Fl(i)/(Pd(i)*A))
Cd = (Fd(i)/(Pd(i)*A))
end
plot(a, Cl);
hold on;
grid on;
plot(a, Cd);
hold on;
grid on;
xlabel('a - Angle of Attack');
ylabel('Cl-(Coefficient of Lift) and Cd-(Coefficicent of Drag)');
title('Coefficients of Lift and Drag vs. Angle of Attack');

Star Strider on 23 Oct 2020
Subscript ‘Cl’ and ‘Cd’ in the loop:
Cl(i) = (Fl(i)/(Pd(i)*A))
Cd(i) = (Fd(i)/(Pd(i)*A))
.

Kane Patrick Bobier on 23 Oct 2020
Thank you! Works perfect.
Star Strider on 23 Oct 2020
As always, my pleasure!