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changeset 10181:7a304f7f9bd5 octave-forge

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control-devel: use filt instead of tf
author paramaniac
date Sun, 06 May 2012 15:53:35 +0000
parents 93615b0e893f
children 3d361bf5be76
files extra/control-devel/inst/arx.m
diffstat 1 files changed, 6 insertions(+), 6 deletions(-) [+]
line wrap: on
line diff
--- a/extra/control-devel/inst/arx.m	Sun May 06 14:32:55 2012 +0000
+++ b/extra/control-devel/inst/arx.m	Sun May 06 15:53:35 2012 +0000
@@ -28,13 +28,13 @@
   PhiU = toeplitz (U(1:end-1, :), [U(1, :); zeros(nb-1, 1)]);
   Phi = [-PhiY, PhiU];
   
-  Theta = Phi \ Y(2:end, :)                 # naive formula
+  ## Theta = Phi \ Y(2:end, :);             # naive formula
   
   ## solve linear least squares problem by pseudoinverse
   ## the pseudoinverse is computed by singular value decomposition
   ## M = U S V*  --->  M+ = V S+ U*
   ## Th = Ph \ Y = Ph+ Y
-  ## Th = V S+ U' Y,   S+ = 1 ./ diag (S)
+  ## Th = V S+ U* Y,   S+ = 1 ./ diag (S)
   
   [U, S, V] = svd (Phi, 0);                 # 0 for "economy size" decomposition, U overwrites input U
   S = diag (S);                             # extract main diagonal
@@ -42,11 +42,11 @@
   V = V(:, 1:r);
   S = S(1:r);
   U = U(:, 1:r);
-  Theta = V * (S .\ (U' * Y(2:end, :)))     # U' is the conjugate transpose
+  Theta = V * (S .\ (U' * Y(2:end, :)));    # U' is the conjugate transpose
   
-  A = [1; Theta(1:na)];     # a0 = 1, a1 = Theta(1), an = Theta(n)
-  B = Theta(na+1:end);      # b0 = 0 (leading zeros are removed by tf, no need to add one)
+  A = [1; Theta(1:na)];                     # a0 = 1, a1 = Theta(1), an = Theta(n)
+  B = [0; Theta(na+1:end)];                 # b0 = 0 (leading zero required by filt)
   
-  sys = tf ({B, 1}, {A, A}, Ts);
+  sys = filt ({B, 1}, {A, A}, Ts);
 
 endfunction
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