Trimming the contours on my plot

No matter what I try, I cannot trim the data of my contour plots. The contours are only supposed to fit inside the regular plot

% AE4802

% Spring 2021

% Assignment 3

clear;

clc;

hold off

plot(0,0)

% Information given in problem statement

W = 35000; % Weight (lbs)

S = 700; % Wing area (ft^2)

CLmax = 1.3; % Maximum lift coefficient

e = 0.75; %oswald efficiency

s = 60;

AR = s^2/S;

h = 15000; % Altitude of 15000 ft

n_max = 3.5; % Limit load factor of 3.5 g's

Vne = 350; % Never Exceed Speed (kts)

g = 32.1741; % Acceleration due to gravity (ft/s^2)

% Problem 3

%----------

% Create an array of load factors

n = 0:0.01:n_max;

K = 1/(pi*e*AR);

% Retreive the density at 15000 ft

[~,~,rho,~,~] = atmosphere(h);

% Calculate velocities (ft/s)

% V = sqrt(vecn.*2.*W./(rho.*S.*CLmax));

% Convert to knots

% kts = V./1.68781;

% calculation for contours

%[Cl,pc] = meshgrid(linspace(0,1.3,351),linspace(21,50,351));

[V,n] = meshgrid(linspace(0,350,351),linspace(0,3.5,351));

V = sqrt(n.*2.*W./(rho.*S.*CLmax));

Cl = linspace(0,1.3,351);

pc = 50.*ones(size(V));

% Convert to knots

kts = V./1.68781;

% Cl = linspace(0,1.3,351);

h = 15000.*ones(size(V));

% pc = 50.*ones(size(Cl));

[temp,pres,rho,mu,a] = atmosphere(h);

M = V./a;

m = W/g;

[thrust, ~, ~] = jt8d(M,h,pc);

CD = dragpolar(Cl,M);

D = 0.5.*rho.*V.^2.*S.*CD;

accel = (thrust - D)./m;

Tmax = jt8d(M,h,50*ones(size(M)));

nstall = (1./2.*W)*rho.*V.^2.*S.*CLmax; % n stall

% Create the plot

% figure()

plot(kts, n,'b') % Creates the Stall Limit

hold on

grid on

plot([kts(end), Vne],[n_max, n_max],'b') % Creates the Structural Load Limit

plot([Vne, Vne],[0, n_max],'b') % Creates the Never Exceed Speed Limit

% Using "end" gives the last element of that array/matrix/etc

% So kts(end) gives the last entry of the array kts

% Set the size of the plot

ylim([0, 4])

xlim([0, 375])

% Add the details

set(gca, 'FontName', 'Times New Roman')

title('V-n Diagram', 'FontName', 'Times New Roman')

xlabel('Airspeed (kts)', 'FontName', 'Times New Roman')

ylabel('Load Factor - n', 'FontName', 'Times New Roman')

% Display the cornering speed

fprintf('The cornering speed is %4.2f knots \n', kts(end));

plot(kts(n==max(n)), max(n),'.r','MarkerSize',20)

text(kts(n==max(n)), max(n),' cornering speed 251.38 kts', 'FontName', 'Times New Roman', 'FontSize', 12, 'Color', 'r', 'VerticalAlignment', 'bottom');

% Calculate and display the corresponding level turn radius in feet

Turn_radius = V(end)^2/(g*sqrt(n_max^2-1));

fprintf('The corresponding level turn radius is %4.2f feet \n', Turn_radius);

% Calculate and display the corresponding turn rate in deg/min at the

% cornering speed

Turn_rate = rad2deg((g*sqrt(n_max^2-1))/V(end)).*60;

fprintf('The corresponding turn rate is %4.2f °/min \n', Turn_rate);

hold on

%plotting contours

Vmargin(V > Vne) = NaN;

nmargin(n>3.5) = NaN;

kts(V > Vne) = NaN;

n_max(V>350) = NaN;

% mask = V > 350;

% V(mask) = NaN;

% n_max(mask) = NaN;

Vmargin(V>350) = NaN;

accel(n>3.5) = NaN;

accel(nstall<n) = NaN;

kts(n<nstall) = NaN;

[c,h] = contour(V(:,351),n(:,1),accel,'LineColor','k');

clabel(c,h,'FontName', 'Times New Roman');

% Save the plot

% print(gcf,'Question_3.png','-dpng','-r400');

[DGM]

I can't run your code, since I don't know what atmosphere() function you're using. If it's a user-defined function, you can attach it.

[Caroline Kenemer]

Here are the other codes

[DGM]

How about dragpolar()?

[Caroline Kenemer]

oh yes sorry

[DGM]

Well, this is a start:

%plotting contours
hiV = (V > 350)'; % <-- need to transpose, since V,n aren't orthogonal anymore
accel(n>3.5) = NaN;
accel(hiV) = NaN;
accel(nstall<n) = NaN; % <-- nstall is huge, so this condition is never met

[c,h] = contour(V(:,351),n(:,1),accel,'LineColor','k');
clabel(c,h,'FontName', 'Times New Roman');

You might want to figure out why nstall is so much larger than n, and whether that's expected.

[Caroline Kenemer]

Here is my updated code once I found the mistake for nstall, but the contours using the suggestion up above stop about halfway through

Answer 1

[DGM]

I was expecting to be able to do:

accel(n>nspeed') = NaN;

but n=nspeed

>> max(n(:,1)-nstall',[],'all')
ans =
   8.8818e-16

n is just a linear ramp.

There's a lot of replicated data here. I was confused as to what was going on for quite some time due to the scaling, but I got it.

hiV = (V>350)';
accel(n>3.5) = NaN;
accel(hiV) = NaN;
accel(V'<kts) = NaN;

[Caroline Kenemer]

You are a lifesaver thank you so much!

[DGM]

No prob. If it's a satisfactory answer, just hit accept so the post gets put in the right category.