  We study the selfmatching properties of Beatty sequences, in particular of
the graph of the function $\lfloor j\beta\rfloor $ against $j$ for every
quadratic unit $\beta\in(0,1)$. We show that translation in the argument by an
element $G_i$ of generalized Fibonacci sequence causes almost always the
translation of the value of function by $G_{i-1}$. More precisely, for fixed
$i\in\N$, we have $\bigl\lfloor \beta(j+G_i)\bigr\rfloor = \lfloor \beta
j\rfloor +G_{i-1}$, where $j\notin U_i$. We determine the set $U_i$ of
mismatches and show that it has a low frequency, namely $\beta^i$.
