% sol1.m 
% Solves the first order differential equation x'=f(t,x) where the 
% function f(t,x) is as defined by the expression in the string variable 
% ftx.  Initial conditions are obtained by clicking the mouse on the 
% desired point inside the graphics window. If the mouse is clicked on a 
% point outside the window then the user is prompted for the initial 
% values directly.

global fstring
fstring=ftx;

disp(' ') 
answer=input('Do you wish to draw a new slope field? (y/n)  ','s') 
if answer=='y' 
 slopef(ftx,N) 
end 

hold on 
 disp('Click on initial point; outside the graphics frame for manual entry.')
 [t0,x0]=ginput(1);
 if (t0<ax(1))|(ax(2)<t0)|(x0<ax(3))|(ax(4)<x0)
	t0=input('t0=');
	x0=input('x0=');
 end

if t0<ax(2)
[s,y]=bdode45('eqn1d',t0,ax(2),x0);                  
plot(s,y,'r') 
xlabel(['t0 = ',num2str(t0),',   x0 = ',num2str(x0)]) 
end

if ax(1)<t0                                
[s,y]=bdode45('eqn1d',t0,ax(1),x0);                  
plot(s,y,'r')
end                                 
                                                 
%hold on