We used the DSFS, the 3D SFS for the observed data. 
The joint 2D SFS files are used to model fitness test.
bifurcate_DSFS.txt is also named bifurcate_DSFS.obs in obs_sfs folder
bifurcate_jointDAFpop1_0.obs, bifurcate_jointDAFpop2_0.obs,bifurcate_jointDAFpop2_1.obs are observed joint 2D derived SFS also named ALPORMSE_jointDAFpop1_0.obs ALPORMSE_jointDAFpop2_0.obs ALPORMSE_jointDAFpop2_1.obs in obs_sfs folder

