function [root1,root2,ier]=quadroots(a,b,c)
%
%   function [root1,root2,ier]=quadroots(a,b,c)
%     Function to find the roots of the quadratic equation given coefficients a,b, and c.
%     This function takes no account of scaling. 
%
    if a==0
%
%  Check odd cases when a=0
%
      if b==0
       if c==0
         ier='all numbers are roots a=b=c=0';
       else
	ier='no roots a=b=0, c ne 0';
       end;
      else
	root1=-c/b;
	root2=root1;
	ier='one root a=0';
      end;
    else
      disc= b*b-4*a*c;
      if disc < 0
%
% Two complex roots computed with real arithmetic
%
	im=sqrt(-disc)/(2*a);
	re=-b/(2*a);
	root1=re+i*im;
	root2=re-i*im;
      else
        if b==0
%
%  Since MATLAB handles complex arithmetic without a blink,
%  we can just use the formula in this case.
%
	  root1=sqrt(-c)/a;
	  root2=-root1;
        else
%
%  Case where there are two real roots.
%
	  diff=sqrt(disc)/(2*a);
	  same=-b/(2*a);
	  if same*diff > 0 
	    root1=same+diff;
          else
	    root1=same-diff;
          end;
	  root2=c/(a*root1);
          end;
        end;
       ier='roots are good';
    end;