function R = Euler11(f,a,b,ya,M)
% - Solve by Euler method  y'=f(t,y) with y(a)=ya
% -  t is in [a,b] .there are(M+1) equal sub-divisions.
% - example R=Euler11('f88',b,ya,M)
% - f88.m is  text file that reads  function f=f88(t,y)
% -                                         f=(t-y)/2 ;
% -                                         return
h=(b-a)/M;
T=zeros(1,M+1);
Y=zeros(1,M+1);
Y(1)=ya;
T=a:h:b;
disp('h=');disp(h);
for j=1:M
   Y(j+1)=Y(j)+h*feval(f,T(j),Y(j));
end
R=[T', Y'];
T=T';
Y=Y';
plot(T,Y);
xlabel(' T ');
ylabel(' Y ');
title(' Eulers  method');
return