ADDED   mttroot/mtt/lib/control/PPP/ppp_int_obs.m
Index: mttroot/mtt/lib/control/PPP/ppp_int_obs.m
==================================================================
--- /dev/null
+++ mttroot/mtt/lib/control/PPP/ppp_int_obs.m
@@ -0,0 +1,27 @@
+function [x_new,y_p] = ppp_int_obs (x,y,U,A,B,C,D,A_u,delta,L)
+
+  ## usage: x_new = ppp_int_obs (x,y,U,A,B,C,D,A_u,delta,L)
+  ##
+  ## Intermittent observer for PPP
+  ##
+  ## x,y Current estimated state and measured output
+  ## U PPP control weights
+  ## A,B,C,D System matrices
+  ## A_u PPP basis matrix
+  ## delta time step
+  ## L Observer gain
+
+  ## Sanity check
+  [n_x,n_u,n_y] = abcddim(A,B,C,D);
+
+  if nargin<10
+    L = zeros(n_x,n_y);
+  endif
+  
+  ## Predictor
+  [y_p,us,x_p] = ppp_ystar (A,B,C,D,x,A_u,U,delta);
+
+  ## Corrector
+  x_new = x_p - L*(y_p-y);
+
+endfunction