d=0.1  %bore dia
l=0.1 %strock length
the=linspace(0,180,180)%theata
cr=12%compression ratio
s_v=(pi/4)*d^2*l %swept volume
c_v=s_v/(cr-1) %clearence volume
con_l=0.2 %connecting rod length
a = l/2%crank pin radius
R=con_l/a

T3=(R*R-(sind(the)).^2).^0.5
T2=R+1-cosd(the)
T1=0.5*(cr-1)
v=(1+T1*(T2-T3))*c_v %getting volume (compression or expanshion)

v1=s_v+c_v
v2=c_v
p1=101325
p2=cr^1.4*p1
c1=p1*v1^1.4
p_com=c1./v.^1.4
t1=500
v3=v2
t2=p2*v2*t1/(p1*v1)
t3=2300
p3=t3*p2/t2
v4=v1
p4=p3*(v3/v4)^1.4
c2=p3*v3^1.4
p_exp=c2./v.^1.4
hold on
plot(v1,p1,'*')
plot(v,p_com,"LineWidth",1) %plotting curved lines 
plot(v2,p2,'*')%plotting in *  form of points
plot(v,p_exp,"LineWidth",1)
plot(v3,p3,'*')
plot(v4,p4,'*')
plot([v2,v3],[p2,p3],"LineWidth",3) %plotting vertical lines
plot([v1,v4],[p1,p4],"LineWidth",3)
efficiency=1-(1/cr^0.4)*100 �ficiency of engine

 �feciency output image