Truncated power function
= Truncated power function
{title2=$(x-t)_+^r$}
For integer $r\ge1$, the truncated power is zero for $x\le t$ and equals $(x-t)^r$ for $x>t$. It is globally $C^{r-1}$ and its $r$th derivative has a jump at $t$. Order zero is the step-function convention $\mathbf1_{\{x>t\}}$. Knot <divided differences> of these functions produce <B-splines>.