Covariance (upper panel) and covariance normalized to the shot-noise level (central panel) as predicted by the Hu & Kravtsov (2003) analytical model (solid lines) and by simulations (dashed lines) for different matrix components: diagonal sample variance terms in blue, diagonal sample variance terms in two different mass bins in red and orange, sample variance between two adjacent redshift bins in green and shot-noise in gray. Lower panel: relative difference between analytical model and simulations. The curves are represented as a function of redshift, in the first mass bin (i = 1).