function [tvec,xvec]=eulstdnt(euler,h,t0,x0,tf) 
% EULSTDNT uses the RHS of an Euler method equation that has been determined 
% symbolically by a student to numerically estimate a solution function for 
% the ODE string variable ftx, using h for the t-step size, t0 & x0 for 
% initial values, and tf for end of t-interval. EULSTDNT returns two 
% vectors: tvec is vector of independent variables; xvec is vector of 
% dependent variables. 

t=t0; x=x0;      % Initialize loop variables 
tvec=t; xvec=x;  % Initialize output vector variables 

while t<tf 
	x=eval(euler);  % determine next x-value via student's RHS 
	if x==inf 
		disp(['Step size ',num2str(h),' gives infinite result for t = ',num2str(t)]) 
		break 
	end 		
	t=t+h;          % update t-value by step size h 
	tvec=[tvec,t];  % update output indepenent variable vector 
	xvec=[xvec,x];  % update output depenent variable vector 
end