function [local_min_x,local_min_y,num_extrema] = localmin(data_x, data_y)
 
% The function LOCALMIN returns local minimum points, their coordinates and the number of values.
%
% Calling sequence-
% [local_min_x,local_min_y,num_extrema] = localmin(data_x, data_y)
%
% Input-
%	data_x		- input vector of coordinates
%	data_y		- input vector of corresponding values
% Output-
%	local_min_x	- vector that specifies the coordinates 
%			        of min values in the order found
%	local_min_y	- corresponding min values
%	num_extrema	- number of min values found

%----- Initialize values
local_min_x = [];
local_min_y = [];
flag = 0;
cnt = 1;
num_extrema = 0;

Y = [];
X = [];

%----- Find the extrema values
for i=2:length(data_y)-1;
        if((data_y(i) == data_y(i+1)) & (flag == 1))
            Y = [Y, data_y(i)];
            X = [X, data_x(i)];
        elseif((data_y(i) < data_y(i-1)) & (flag == 0)) & ~(data_y(i) == data_y(i-1))
            flag = 1;
            Y = data_y(i);
            X = data_x(i);
        end
        
        if((data_y(i) > data_y(i+1)) & (flag == 1))
            flag = 0;
            Y = [];
            X = [];
        end
        
        if((data_y(i) < data_y(i+1) & (flag == 1)))
            flag = 0;
            local_min_y = [local_min_y, Y];
            local_min_x = [local_min_x, X];
            Y = [];
            X = [];
            num_extrema = num_extrema+1;
        end
end