So I've got a system of equations. One equation is very long. I want them all aligned, but I want the long equation to split over two lines.
\begin{align}
\theta &= \theta(t-1) -p \theta(t-1) +p
\frac{\hat{\psi}'(\theta(t-1))}{\ave{K}} +p \phi_R(0)\nonumber\\
&\qquad + (1-p)(1-\theta(t-1))\\
R &= R(t-1)+I(t-1)
\end{align}
As it stands, the equation for \theta
spans two lines and is numbered on the second line. I'd like the number to be centered (rather like split appears to do). I haven't found a good way to do this.
aligned
insideequation
.