plot_stress_diag

% function to plot stress diagram of a simple beam that
% has it's steel yielding
function plot_stress_diag(h,d,c,fc,a,fy)
% Plot lines
hold on
title("Stress diagram")
xlabel("\sigma (ksi)")
ylabel("y (in)")
% Put some annotations
% sigma at concrete
text(mean([0 0.85*fc]),h+1,num2str(0.85*fc),"HorizontalAlignment","center","Color",'red')
% sigma at steel
text(mean([-fy 0]),(h-d)+1,strcat("fs = ",num2str(fy)),"HorizontalAlignment","center","Color",'b')
% Annotation line for c
plot([-10 -10],[h-c h],'Color',0.5*[1 1 1] )
plot([-10 0],[h h],'--','Color',0.5*[1 1 1] )
plot([-10 0],[h-c h-c],'--','Color',0.5*[1 1 1] )
% text for c
text(-10,mean([h h-c]),strcat("c = ",num2str(c)),"HorizontalAlignment","center","Rotation",90,"BackgroundColor","white")
% Annotation line for h
plot([15 15],[0 h],'Color',0.5*[1 1 1] )
plot([0.85*fc 15],[h h],'--','Color',0.5*[1 1 1] )
plot([0 15],[0 0],'--','Color',0.5*[1 1 1] )
% text for h
text(15,mean([h 0]),strcat("h = ",num2str(h)),"HorizontalAlignment","center","Rotation",90,"BackgroundColor","white")
% Annotation line for d
plot([-15 -15],[h-d h],'Color',0.5*[1 1 1] )
plot([-15 0],[h h],'--','Color',0.5*[1 1 1] )
plot([-15  0],[h-d h-d],'--','Color',0.5*[1 1 1] )
% text for d
text(-15,mean([h-d h]),strcat("d = ",num2str(d)),"HorizontalAlignment","center","Rotation",90,"BackgroundColor","white")
% Annotation line for a
plot([9 9],[h-a h],'Color',0.5*[1 1 1] )
plot([9 0],[h h],'--','Color',0.5*[1 1 1] )
plot([9  0],[h-a h-a],'--','Color',0.5*[1 1 1] )
% text for a
text(9,mean([h-a h]),strcat("a = ",num2str(a)),"HorizontalAlignment","center","Rotation",90,"BackgroundColor","white")
% plot vertical line of beam
plot([0 0],[0 h],'Color','black')
% plot neutral axis
plot([-fy 4*0.85*fc],[h-c h-c],'-.','Color',0.8*[1 1 1])
% plot vertical line of compression stress
plot([0.85*fc   0.85*fc],[h   h-a],'Color','red')
% Create 4 arrows that go from the red vertical line to the black vertical
% line
ys_arrows = linspace(0,a,4) + h-a;
for i = 1:length(ys_arrows)
    anArrow = annotation('arrow') ;
    anArrow.Parent = gca;
    x_start = 0.85*fc;
    y_start = ys_arrows(i);
    delta_x = -x_start;
    delta_y = 0;
    anArrow.Position = [x_start, y_start, delta_x, delta_y];
    anArrow.Color = 'red';
end
% Plot steel stress arrow
anArrow = annotation('arrow') ;
anArrow.Parent = gca;
x_start = -fy;
y_start = h-d;
delta_x = -x_start;
delta_y = 0;
anArrow.Position = [x_start, y_start, delta_x, delta_y];
anArrow.Color = 'blue';
end