Update docstring for lqr

cwrowley · cwrowley · commit 262479061bcd · 2015-04-18T17:07:40.000-04:00
diff --git a/control/statefbk.py b/control/statefbk.py
@@ -147,7 +147,7 @@ def lqr(*args, **keywords):
     The lqr() function computes the optimal state feedback controller
     that minimizes the quadratic cost
 
-    .. math:: J = \int_0^\infty x' Q x + u' R u + 2 x' N u
+    .. math:: J = \int_0^\infty (x' Q x + u' R u + 2 x' N u) dt
 
     The function can be called with either 3, 4, or 5 arguments:
 
@@ -156,6 +156,9 @@ def lqr(*args, **keywords):
     * ``lqr(A, B, Q, R)``
     * ``lqr(A, B, Q, R, N)``
 
+    where `sys` is an `Lti` object, and `A`, `B`, `Q`, `R`, and `N` are
+    2d arrays or matrices of appropriate dimension.
+
     Parameters
     ----------
     A, B: 2-d array
