Arrowhead is turning the wrong way

The arrowhead is pointing the wrong way in the x-axis. See figure below.

Definerer alle landes forskydningsbæreevne
clc; clear; close all; clc ;

Forhold = 1/2 ;
Forhold2 = 54/228;


f_vk0 = 0.4 ; % Klæbningsbidrag [MPa]
mu_k = 0.65 ; % Friktionskoefficient
f_bt = 1.00 ; % Trækstyrke af sten [MPa]
f_k = 10.00 ; % Trykstyrke af sten [MPa]

sigma1 = -0.0:0.1:1.6 ;
sigma2 = 0.1:0.1:10.2; 
sigma3 = 8.3:0.1:10 ;

sigma23 = 9.1:0.1:10 ;


Friction = (f_vk0 + mu_k * sigma1) / (1 + mu_k * 2 * Forhold) ;
Tension_failure = f_bt / 2.3 * sqrt(1 + sigma2/f_bt) ;
Compression_failure = (f_k - sigma3) * 1/Forhold*(1/2) ;

Friction2 = (f_vk0 + mu_k * sigma1) / (1 + mu_k * 2 * Forhold2) ;
Tension_failure = f_bt / 2.3 * sqrt(1 + sigma2/f_bt) ;
Compression_failure2 = (f_k - sigma23) * 1/Forhold2*(1/2) ;



Plotter forskydningsbæreevnerne
hf = figure() ;
hold on
plot(sigma1, Friction,'--','Color',[0.4660 0.6740 0.1880],'LineWidth',1.3)
plot(sigma2, Tension_failure,'--','Color',[0.9290 0.6940 0.1250],'LineWidth',1.3)
plot(sigma3, Compression_failure,'--','Color',[0.4940 0.1840 0.5560],'LineWidth',1.3)

plot(sigma1, Friction2,'LineWidth',1.3)
plot(sigma2, Tension_failure,'Color',[0.6350 0.0780 0.1840],'LineWidth',1.3)
plot(sigma23, Compression_failure2,'Color',[0.8500 0.3250 0.0980],'LineWidth',1.3)

% Shade the area between [sigma1, Friction] and [sigma1, Friction2]
% fill([sigma1, fliplr(sigma1)], [Friction, fliplr(Friction2)], [0.7 0.7 0.7], 'EdgeColor', 'none');

grid on;

xlim([0 12])
ylim([0 2])


% Shade the area between [sigma1, Friction] and [sigma1, Friction2]
[x0,y0,~,~] = intersections(sigma1,Friction,sigma2, Tension_failure);
ind = (sigma1<x0);
sigma1b = [sigma1(ind) x0]; % add x0 of true intersection point
Frictionp = [Friction(ind) y0]; % add y0 of true intersection point
[x1,y1,~,~] = intersections(sigma1,Friction2,sigma2, Tension_failure);
ind = (sigma1<x1);
sigma1c = [sigma1(ind) x1]; % add x1 of true intersection point
Friction2p = [Friction2(ind) y1]; % add y1 of true intersection point

% fill([sigma1, fliplr(sigma1)], [Friction, fliplr(Friction2)], [0.7 0.7 0.7], 'EdgeColor', 'none');
tt = fill([sigma1b, fliplr(sigma1c)], [Frictionp, fliplr(Friction2p)], [0.6350 0.0780 0.1840],'FaceAlpha',0.0,'EdgeColor', 'none');
hatchfill2(tt,'single','HatchAngle',-45,'HatchDensity',90,'HatchColor',[0.6350 0.0780 0.1840],'HatchLineWidth',1)

% Shade the area between [sigma3, Compression_failure] and [sigma3, Compression_failure2 ]
[x01,y01,~,~] = intersections(sigma3, Compression_failure,sigma2,Tension_failure);
ind = (sigma3>x01);
sigma1b = [x01 sigma3(ind)]; % add x0 of true intersection point
Frictionp = [y01 Compression_failure(ind)]; % add y0 of true intersection point
[x11,y11,~,~] = intersections(sigma23, Compression_failure2,sigma2,Tension_failure);
ind = (sigma23>x11);
sigma1c = [x11 sigma23(ind)]; % add x1 of true intersection point
Friction2p = [y11 Compression_failure2(ind)]; % add y1 of true intersection point

% fill([sigma1, fliplr(sigma1)], [Friction, fliplr(Friction2)], [0.7 0.7 0.7], 'EdgeColor', 'none');
tt2 = fill([sigma1b, fliplr(sigma1c)], [Frictionp, fliplr(Friction2p)], [0.6350 0.0780 0.1840], 'EdgeColor', 'none','FaceAlpha',0.0);

hatchfill2(tt2,'single','HatchAngle',-45,'HatchDensity',90,'HatchColor',[0.6350 0.0780 0.1840],'HatchLineWidth',1)

hax = gca;
hax.XDir = 'reverse'; % flip axis direction
hax.YAxisLocation = 'right'; % move ticks & labels to the other side

xlim([-2 12])
ylim([-0.5 2])

ha.Parent = hf.CurrentAxes;  % associate annotation with current axes
% now you can use data units
ha.X = [-1.5 11];
ha.Y = [0 0] ;

%Define the variable
xac = -2; %x arrow coordinate
yac = 0; %y arrow coordinate
xas = 12;   %x arrow shift
yas = 0;   %y arrow shift


ha = annotation('arrow');
ha.Parent = hf.CurrentAxes;  % associate annotation with current axes
% now you can use data units
ha.X = [-1.5 11];
ha.Y = [0 0] ;

ha = annotation('arrow');
ha.Parent = hf.CurrentAxes;  % associate annotation with current axes
% now you can use data units
ha.X = [0 0];
ha.Y = [-0.4 2] ;

% remove old box and axes
box on
set(gca,'YColor',get(gca,'Color'))
set(gca,'XColor',get(gca,'Color'))
set(gca, 'FontName', 'Times New Roman', 'FontSize', 14)
set(gca, 'XTickLabel', {});
set(gca, 'YTickLabel', {});

legend({'Friction failure (M&M)','Tension failure (M&M)','Compression failure (M&M)','Friction failure (DK)','Tension failure (DK)','Compression failure (DK)'},'Location','northeast','NumColumns',1,'Orientation','vertical')

[Michel bertrand]

Try negative head lenght, ha.HeadLength=-10; this works for me in a similar situation.

Answer 1

[VBBV]

Hi @Rasmus Bruun, In this line, you are trying to reverse the direction of X-axis (for unknown reason), If you comment the below line, the arrow head of x-axis graph seems to be fine

% hax.XDir = 'reverse'; % flip axis direction

[Rasmus Bruun]

Thank you for your response!

Yes you are correct about making the arrow turn correct as below. But the reverse of the x-axis mirrors the envelope drawn between the arrows around the y-axis. This ensures the correct form but unfortunate the arrowhead is not reversing like the rest of it.