solving otto cycle using matlab

The assignmnet was to find out how to join the remaining two lines.It took me some atteamps to get through but since now its done so i'm publishing it as my assignment.

clear all
close all
clc

%input
gamma=1.4
t3=2300
%state variable 
p1=100000
t1=500

%engine geometric parameters

bore=0.1;
stroke=0.1;
con_rod=0.15;
cr=12;

%calculating swept volume & cleaarance volume

v_swept=(pi/4)*bore^2*stroke;
v_clearance=v_swept/(cr-1);

v1=v_swept+v_clearance
v2=v_clearance

%state variables for state point 2

p2=p1*cr^gamma;

%p1v1/t1=p2v2/t2

t2=p2*v2*t1/(p1*v1)

constant_c=p1*v1^gamma;
V_compression=piston(bore,stroke,con_rod,cr,180,0);

P_compression=constant_c./V_compression.^gamma;


%state vriable at point 3

v3=v2


%p3v3/t3=p2v2/t2

p3=p2*t3/t2

constant_c=p3*v3^gamma;
V_expansion=piston(bore,stroke,con_rod,cr,0,180);

P_expansion=constant_c./V_expansion.^gamma;

%state variable at point 4

v4=v1

%p3v3^gamma=p4v4^gamma

p4=p3*(v3/v4)^gamma

%plotting

figure(1)
hold on

plot(v1,p1,'*','color','r')
plot(V_compression,P_compression)
plot(v2,p2,'*','color','r')
plot([v2 v3],[p2 p3],'color','g')
plot(v3,p3,'*','color','r')
plot(V_expansion,P_expansion)
plot(v4,p4,'*','color','r')
plot([v4 v1],[p4 p1],'color','b')



xlabel('volume')
ylabel('pressure')