function   num=ent_num(mat,lb,up)
% num=ent_num(mat,lb,up)
% 
% Input: mat - a matrix
%        lb - lower bound
%        up - upper bound
% Output: returns the number of entries in mat that are >= lb and <= up.
%

a=mat>=lb & mat<=up;
num=sum(a(:));
fprintf('Number of entries greater than %d and less than %d is %d \n',lb,up,num);