PlotHaighTheory.m

%function PlotHaighTheory()
% x=-1.06:0.001:1.06;
% z=0.35.*x-sqrt((0.1225)+1-x.*x);
% y=0.35.*x+sqrt((0.1225)+1-x.*x);
% plot(x,y,x,z)
%function PlotHaighTheory(sigma0,v)

 %a = num2str(v);
 %f1 = 'x^2+y^2-2*.35*x*y-1';
 %h = ezplot(f1);

 % to change the axis length
%axis([ -2*sigma0 2*sigma0 -2*sigma0 2*sigma0]);
% to show grid and minor grid
%grid on
%grid minor
% setting title 
%title('St Venaant Theory')
% setting label of x and y axis
%xlabel('Sigma1')
%ylabel('Sigma2')   
%end  
function plotHaighTheory(p)
 x=-1.07:0.001:1.07;    %generating a grid
 z=p.*x-sqrt((((p*p)-1).*x.*x)+1);    %lower half of ellipse
 y=p.*x+sqrt((((p*p)-1).*x.*x)+1);  %upper half of ellipse
plot(x,y,x,z,'color',[0,0.7,0.9])         %plotting the graph

% to show grid and minor grid
grid on
grid minor
% setting titlegit push
title('Haigh Theory')
% setting label of x and y axis
xlabel('σ1/σY')
ylabel('σ2/σY')