I'm not getting table

%Step 1:

% define function

function Assignment3part3()% Function will be in loop

function result = f_example(x,t)

%rhs functions in ODEs

result (1) = -15.068 * x(1) + 3.623*x(2) + 1; %Rate 1

result (2) = 6.973 * x(1) - 13.61*x(2) + 3.371; %Rate 2

end

function [tstore,xstore] = solve_euler (f, t0, x0, deltat, jstep, mtime)

% solutions of systems of ODEs by eluer stepping

% f (function f(x,t) that supplies right-hand sides of ODEs

% t0 initial time

% x0 initial value of vector x

% deltat time step

% jstep number of time steps between stored results

% mtime number of stored rsults after time t0

% tstore(m+1) = time at stored step m

% xstore(m+1,:)= solution vector x at stored step m

% Step 2:

% initial values

t= t0;

x= x0;

tstore( 1) =t;

xstore(:,1)=x';

% Step 3:

%time stepping

for m = 1 :mtime

for j =1 :jstep

x =x + f(x) * deltat;

t = t + deltat;

end

tstore( m+1) = t;

xstore(:,m+1) = x';

end

end

function write_table (tstore,xstore)

%Step 4

%report X1, X2 and t

fileID = fopen ('table.txt','w');

fprintf(fileID, ' t x(1) x(2)\r\n');

fprintf(fileID, '------ -------- ---------\r\n');

for m = 1 : length (tstore)

fprintf(fileID,'%6.3f %9.6f %9.6f\r\n',...

tstore(m), xstore(1,m), xstore(2,m));

end

end

% Step 5:

function plot_graph_1(tstore,xstore)

%plot results time dependence of x(1) and x(2)

plot (tstore,xstore(1,:),'r-o',...

tstore,xstore(2,:),'b-o')

xlabel('{\it t}')

ylabel('{it\ x}_{1}, {\it x}_{2}')

title('Time dependence of {\it x}_{1} and {\it x}_{2}')

axis ([0 0.5 0 1])

end

function plot_graph_2 (xstore)

%plot results:phase portrait of x(1) and x(2)

plot(xstore(1,:), xstore(2,:),'r-o')

xlabel('{\it x}_{1}')

ylabel('{\it x}_{2}')

title('phase portrait of {\it x}_{1} and {\it x}_{2}')

axis([0 1 0 1])

end

x1=[1,0.5,0,0,0,0.5];

x2=[0,0.5,1,0.5,0,0];

for i=1:length(x1)

%now we need results for ith value of x1 and x2

[tstore, xstore] = solve_euler (@f_example, 0, [x1(i),x2(i)], 0.0005,100,15);

write_table(tstore, xstore);

figure(1)

plot_graph_1(tstore,xstore);

hold on

figure(2)

plot_graph_2(xstore);

hold on

end

end

Answer 1

[Star Strider]

It works when I run it, and with:

q = which('table.txt', '-all')
type(q{:})

produces:

     t        x(1)        x(2)
------    --------   ---------
 0.000     0.500000     0.000000
 0.050     0.287527     0.215511
 0.100     0.203881     0.291050
 0.150     0.170115     0.315941
 0.200     0.155981     0.323072
 0.250     0.149770     0.324344
 0.300     0.146874     0.323933
 0.350     0.145433     0.323218
 0.400     0.144670     0.322596
 0.450     0.144244     0.322141
 0.500     0.143997     0.321830
 0.550     0.143849     0.321626
 0.600     0.143759     0.321493
 0.650     0.143704     0.321409
 0.700     0.143669     0.321356
 0.750     0.143648     0.321322

This seems to be what you want.

Note that you are writing to a file, so you need to actually print the file if you want to see the output!