Horizontal line up to graph line

Hi everyone,

I want to put horizontal line to my graph . The line extend up to end of the graph however it should be cut at point to graph line and horizontal line intersect. Also I want to change chracter to subscript 1 in S1 . How I do it? Thanks.

clear
clc
y = [0.5 1 2 3.5 6 8 10.2 14 18 21 35 41 58 60.5 66 70 90 100];  
y1 = [0 0.5 1 2 3.5 6 8 10.2 14 18 21 35 37.32]; % Trapezoidal integralin tanım aralığı (y1)
u = [0.271 0.518 1.113 1.93 3.137 4.157 5.32 7.28 9.22 10.79 11.3 11.52 11.55 11.51 11.58 11.6 11.59 11.50];
u1 = [0 0.271 0.518 1.113 1.93 3.137 4.157 5.32 7.28 9.22 10.79 11.3 11.385] % Trapezoidal integralin tanım aralığı (u1)
U = u(end); % Free stream velocity
u99=0.99.*U;
L=interp1(u(1:13),y(1:13),u99); % Sınır tabakası


S1 = trapz(y1,1-u1/U); % Integral of (1-u/U) w.r.t. y
S2 = trapz(y1,(u1/U).*(1-u1/U)); % Integral of (u/U)*(1-u/U) w.r.t. y
S3 = trapz(y1,(u1/U).*(1-(u1.*u1)/(U.*U))); % Integral of (u/U)*(1-(u/U)^2) w.r.t. y
fprintf('\nU = %6.2f (mm)\ndelta1 = %6.2f (mm)\ndelta2 = %6.2f (mm) \ndelta3 = %6.2f (mm)\n',...
    U,S1,S2,S3);

plot(u,y,'p-','LineWidth',1,'Marker','square'); xlabel('u (m/s)'); ylabel('y (mm)');

hold on
plot([0 U],S1*[1 1],'r--','color',[0 0 1]); % yatay cizgi y = S1
theText = sprintf('\\delta1 = %4.3f',S1);
text(0.05*U,1.2*S1,theText,'FontSize',12); % yazı karakteristikleri

Answer 1

[Star Strider]

Try this —

y = [0.5 1 2 3.5 6 8 10.2 14 18 21 35 41 58 60.5 66 70 90 100];  
y1 = [0 0.5 1 2 3.5 6 8 10.2 14 18 21 35 37.32]; % Trapezoidal integralin tanım aralığı (y1)
u = [0.271 0.518 1.113 1.93 3.137 4.157 5.32 7.28 9.22 10.79 11.3 11.52 11.55 11.51 11.58 11.6 11.59 11.50];
u1 = [0 0.271 0.518 1.113 1.93 3.137 4.157 5.32 7.28 9.22 10.79 11.3 11.385]; % Trapezoidal integralin tanım aralığı (u1)
U = u(end); % Free stream velocity
u99=0.99.*U;
L=interp1(u(1:13),y(1:13),u99); % Sınır tabakası
S1 = trapz(y1,1-u1/U); % Integral of (1-u/U) w.r.t. y
S2 = trapz(y1,(u1/U).*(1-u1/U)); % Integral of (u/U)*(1-u/U) w.r.t. y
S3 = trapz(y1,(u1/U).*(1-(u1.*u1)/(U.*U))); % Integral of (u/U)*(1-(u/U)^2) w.r.t. y
fprintf('\nU = %6.2f (mm)\ndelta1 = %6.2f (mm)\ndelta2 = %6.2f (mm) \ndelta3 = %6.2f (mm)\n',...
    U,S1,S2,S3);

U =  11.50 (mm)
delta1 =  11.64 (mm)
delta2 =   4.21 (mm) 
delta3 =   6.55 (mm)

Ui = interp1(y, u, S1)                                                      % 'u' Limit (Intercept) Of Dashed Line

Ui = 6.0630

plot(u,y,'p-','LineWidth',1,'Marker','square'); xlabel('u (m/s)'); ylabel('y (mm)');
hold on
plot([0 Ui],S1*[1 1],'r--','color',[0 0 1]); % yatay cizgi y = S1
% plot([0 U],S1*[1 1],'r--','color',[0 0 1]); % yatay cizgi y = S1
theText = sprintf('\\delta_1 = %4.3f',S1);                                  % Convert To Subscript
text(0.05*U,1.2*S1,theText,'FontSize',12, 'Vert','bottom'); % yazı karakteristikleri

The dashed line now only extends to the point of interception with the blue line.

.

Answer 2

[Chunru]

y = [0.5 1 2 3.5 6 8 10.2 14 18 21 35 41 58 60.5 66 70 90 100];  
y1 = [0 0.5 1 2 3.5 6 8 10.2 14 18 21 35 37.32]; % Trapezoidal integralin tanım aralığı (y1)
u = [0.271 0.518 1.113 1.93 3.137 4.157 5.32 7.28 9.22 10.79 11.3 11.52 11.55 11.51 11.58 11.6 11.59 11.50];
u1 = [0 0.271 0.518 1.113 1.93 3.137 4.157 5.32 7.28 9.22 10.79 11.3 11.385] % Trapezoidal integralin tanım aralığı (u1)

u1 = 1×13

0 0.2710 0.5180 1.1130 1.9300 3.1370 4.1570 5.3200 7.2800 9.2200 10.7900 11.3000 11.3850

U = u(end); % Free stream velocity
u99=0.99.*U;
L=interp1(u(1:13),y(1:13),u99); % Sınır tabakası
S1 = trapz(y1,1-u1/U); % Integral of (1-u/U) w.r.t. y
S2 = trapz(y1,(u1/U).*(1-u1/U)); % Integral of (u/U)*(1-u/U) w.r.t. y
S3 = trapz(y1,(u1/U).*(1-(u1.*u1)/(U.*U))); % Integral of (u/U)*(1-(u/U)^2) w.r.t. y
fprintf('\nU = %6.2f (mm)\ndelta1 = %6.2f (mm)\ndelta2 = %6.2f (mm) \ndelta3 = %6.2f (mm)\n',...
U,S1,S2,S3);

U =  11.50 (mm)
delta1 =  11.64 (mm)
delta2 =   4.21 (mm) 
delta3 =   6.55 (mm)

plot(u,y,'p-','LineWidth',1,'Marker','square'); xlabel('u (m/s)'); ylabel('y (mm)');
hold on
% plot([0 U],S1*[1 1],'r--','color',[0 0 1]); % yatay cizgi y = S1

yline(S1, 'b--');                                            % horizontal line
theText = sprintf('\\delta_1 = %4.3f',S1);                  % use _ for subscript

text(0.05*U,1.2*S1,theText,'FontSize',12); % yazı karakteristikleri

[jack london]

Thank you but it still seems to extend after graph line. I want to trim at point the graph line and horizontal line intersect(about u=6).