Diwash Panta

I am planning to carry out the analysis of existing plan irregular L-shaped building using Response Spectrum method . The method will be carried out based upon IS code 1893 using Etabs. I really got confused of checking of eccentricity using response spectrum method. For response spectrum method , in Etabs after assigning of the load cases we could find the eccentricity overviews options per floor diaphragm. But it doesnot take the negative value. Thus, how could we use the four load combination for the check of eccentricity for response spectrum method.