function  nt= plot4(t,c,i)
 
% The function PLOT4 plots 4 subplots starting from the I-th component
% of the data c(n,k), where n is the number of data points and
% k is the number of IMF components.
% The number of subplots in vertical and horizontal direction is equal 2.
% The image on the screen closes all existing figures.
%
% Calling sequence-
% nt=plot4(t,c,i)
%
% Input-
%	t		    - vector t(n) representing the 
%				time scale values
%	c		    - component data array c(n,k)
%	i		    - index of the first plotted component 
% Output-
%	nt		    - the handle of the figure
 
% Z. Shen (Caltech)		Initial

close;

tn=length(t);
for j=i:i+3
   subplot(2,2,j+1-i),plot(t,c(:,j));
   axis([t(1) t(tn) min(c(:,j)) max(c(:,j))]);	
   s1='c';
   s2=[s1 num2str(j)];
   title(s2);
end
nt=1;