if sced ==0;
	sigma = (((sigma2-sigma1)/(4)).*(xdata+2))+(sigma1);
elseif sced ==1;
	sigma = (((sigma2-sigma1)/(4)).*(xdata+2))+(sigma1);
elseif sced ==2;
	sigma = (2.^(get(sli_noise, ''Val''))).*(xdata);
else;
	sigma = 0;
end;
	
