If I want modify the parameters file (code)  --"NsNsToHMNS.par" of the binary neutron stars in the "gallery example" to simulate the non vacuum binary neutron stars (and the gas surrounding could be in different density and velocity distribution, should I add some thorns into the parameters file(NsNsToHMNS.par )? if yes, what should I add? )how could I do ?  

thank you~~