How can I combine these two codes

I need help creating a plot of streamlines over an ellipse for a school assignment

The two codes that I am using are

% Plot streamlines and pressure coefficent of an unviscious,uncomprimibile,irrotational 
% flow around a cylinder section (radius = 1) that spins around the z axis (coming out 
% of the xy plane). 
% This result is achieved by superimposition of elementary solution of the potential 
% function PHI, where [Ux , Uy] = GRAD(PHI) which comprehend Uniform Stream,Doublet,Vortex. 
% This case rappresents a good example of Magnus Effect,that is the reason why spinning 
% balls have an effected trajectory.And rappresent the basis of Kutta-Joukowski theory. 
% 
% 
% INPUT 
% V_i = Asymptotic Speed 
% G = Angular Speed (positive anti-clockwise) 
% 
% -----EXAMPLE------ 
% V_i = 20 
% G = 50 
% 
% Created by: Dario Isola 
% DATA : 24/03/2004 
% Politecnico di Milano - Aerospatial Engeeniering Departement 
%---------- 
%Modification log 
%Author Date Description 
%---------------------------------------------------------------------------------- 
%Yogesh PARTE,IMT Toulouse 15 Jan 2010 Added Cp distribution plot
% over a cylinder see 
% figure(4), removed for loop, added comments 
%----------------------------------------------------------------------------------

close all;

clear all;

%%Input section 
V_i = input(' Asymptotic speed V_0 [m/s] = '); 
G = input(' Circulation Value G [rad/s] [Anti-clockwise] = ');

%%Actual computation 
%Radius of the circle 
a = 3.5 ;
c =-a*2;
b =a*2;

% Number of intervals 
n =a*50;

[x,y]=meshgrid([c:(b-c)/n:b],[c:(b-c)/n:b]');

warning off;

%%Preliminary DATA & purification

% Set values of X and Y inside the cylinder to zero 
[I J]=find( (x.^2+y.^2) < a);

if ~isempty(I) 
x(I,J) = 0; 
y(I,J) = 0; 
end

%Definition of polar variables 
rho=sqrt(x.^2+y.^2);

theta=atan2(y,x);

% Creation of the streamline function 
z=V_i.*sin(theta).*rho.*(1-(a^2./(rho.^2)))-G*log(rho)/(2*pi);

%%Generate unite cicle for plotting 
n=100; 
r=ones(1,n+1)*a; 
t=[0:2*pi/n:2*pi];

Xcircle = r.*cos(t); 
Ycircle = r.*sin(t); 
%%Plot the data

% Streamline Plot 
figure(1); 
contour(x,y,z,25); 
colorbar; 
hold on; 
fill(Xcircle,Ycircle,'k'); 
title('Stream Lines'); 
xlabel('x \rightarrow'); 
ylabel('y \rightarrow'); 
axis square;

This is code that I found online for streamlines over a circle.

The other code is

clc,clear
a=5.5; %horizontal radius
b=3.50; %vertical radius
x0=0; % x0,y0 ellipse centre coordinates
y0=0;
t=-pi:0.01:pi;
x=x0+a*cos(t);
w=y0+b*sin(t);
plot(x,w)
grid on

This is to plot an ellipse.

My problem is that I need the second code to be somehow integrated into the first code which is the stream line code.

Any help would be great because my professor would like to see some sort of MATLAB use out of our project.

Thank you.

Answer 1

[Geoff Hayes]

Haim - just convert the second script into a function so that you can call it from the first function (make sure that you acknowledge the author of this code, Azzi Abdelmalek at http://www.mathworks.com/matlabcentral/answers/86615-how-to-plot-an-ellipse). Do something like

 function [x,w] = getEllipse(a,b,x0,y0)
 % a - horizontal radius
 % b - vertical radius
 % x0,y0 ellipse centre coordinates

 t=-pi:0.01:pi;
 x=x0+a*cos(t);
 w=y0+b*sin(t);

[Haim Matharu]

Geoff,

I appreciate your help, I just can't seem to get it working correctly. I have been changing the streamline to work with the function, but it does not seem to be working.

[Geoff Hayes]

Haim - how have you changed the code? Please describe what you have tried to do and what errors you are encountering.