From 68a24f3a9c971c54966aedec9b5b59849d1d1f77 Mon Sep 17 00:00:00 2001
From: Thorsten Liebig <thorsten.liebig@gmx.de>
Date: Sun, 9 Dec 2012 22:05:00 +0100
Subject: [PATCH] matlab: auto regressive model update, use error code to
 return status

Signed-off-by: Thorsten Liebig <thorsten.liebig@gmx.de>
---
 matlab/AR_estimate.m | 60 +++++++++++++++++++++++++++++++++++++-------
 1 file changed, 51 insertions(+), 9 deletions(-)

diff --git a/matlab/AR_estimate.m b/matlab/AR_estimate.m
index 269445d..ab6e293 100644
--- a/matlab/AR_estimate.m
+++ b/matlab/AR_estimate.m
@@ -1,8 +1,8 @@
-function [val_ar t_ar f_val_ar] = AR_estimate( t, val, freq, nu, mu, expand_factor)
-% [val_ar t_ar f_val_ar] = AR_estimate( t, val, freq, < nu, mu, expand_factor >)
+function [val_ar t_ar f_val_ar EC] = AR_estimate( t, val, freq, nu, mu, expand_factor)
+% [val_ar t_ar f_val_ar  EC] = AR_estimate( t, val, freq, < nu, mu, expand_factor >)
 %
 % apply autoregressive signal model to improve dft results
-%  
+%
 % t     : time vector
 % val   : time domain values
 % freq  : frequency vector for dft
@@ -12,15 +12,37 @@ function [val_ar t_ar f_val_ar] = AR_estimate( t, val, freq, nu, mu, expand_fact
 % mu    : number of timesteps to train the model (default 3*nu)
 % expand_factor : increase signal length by this factor (default 5)
 %
-% 
+% return values:
+% val_ar:   AR estimated time signal
+% t_ar:     time vector
+% f_val_ar: FD transformed AR estimated signal
+% EC:       error code
+%           0 --> no error
+%           1 --> input error: t and val mismatch
+%           2 --> input error: mu has to be larger than 2*nu
+%           3 --> inout error: expand_factor has to be larger than 1
+%           10 --> AR error: signal is to short for AR estimate --> decrease AR order
+%           11 --> AR error: estimated signal appears to be unstable --> use a different mu
+%
 % openEMS matlab interface
 % -----------------------
 % Author: Thorsten Liebig, 2011
 %
 % See also ReadUI, DFT_time2freq
 
+EC = 0;
+val_ar = [];
+t_ar = [];
+f_val_ar = [];
+
+
 if numel(t) ~= numel(val)
-    error 'numel(t) ~= numel(val)'
+    if (nargout<4)
+        error 'numel(t) ~= numel(val)'
+    else
+        EC = 1;
+        return
+    end
 end
 
 if (nargin<4)
@@ -34,11 +56,21 @@ if (nargin<6)
 end
 
 if (mu<=2*nu)
-    error 'mu should be larger than 2*nu'
+    if (nargout<4)
+        error 'mu has to be larger than 2*nu'
+    else
+        EC = 2;
+        return
+    end
 end
 
 if (expand_factor<=1)
-    error 'expand_factor must be larger than 1'
+    if (nargout<4)
+        error 'expand_factor has to be larger than 1'
+    else
+        EC = 3;
+        return
+    end
 end
 
 dt = t(2)-t(1);
@@ -46,7 +78,12 @@ dt = t(2)-t(1);
 M = numel(t);
 
 if (M<0.6*mu)
-    error 'signal is to short for AR estimate --> decrease AR order'
+    if (nargout<4)
+        error 'signal is to short for AR estimate --> decrease AR order'
+    else
+        EC = 10;
+        return
+    end
 end
 
 for n=1:mu-nu
@@ -67,7 +104,12 @@ for k=M:expand_factor*M
 end
 
 if (max(val_ar(M:end)) > max(val))
-    error 'estimated signal appears to be unstable --> use a larger mu'
+    if (nargout<4)
+        error 'estimated signal appears to be unstable --> use a different mu'
+    else
+        EC = 11;
+        return
+    end
 end
 
 f_val_ar = DFT_time2freq(t_ar, val_ar, freq);