2016-11-29: lower uncertainty

lower uncertainty

diff --git a/examples/ensemble-estimation.w b/examples/ensemble-estimation.w
--- a/examples/ensemble-estimation.w
+++ b/examples/ensemble-estimation.w
@@ -181,7 +181,7 @@ x are parameters to be optimized, pos is
 ;; the equivalent of measured observations
 define y^true : list-ec (: i y⁰-pos) : H x^true i
 ;; now we disturb the observations with a fixed standard deviation. This assumes uncorrelated observations.
-define y⁰-std 100
+define y⁰-std 30
 define y⁰ : list-ec (: i y^true) : + i : * y⁰-std : random:normal
 ;; and define the covariance matrix. This assumes uncorrelated observations.
 define R : make-covariance-matrix-from-standard-deviations : list-ec (: i y⁰-num) y⁰-std