code changes by Kartik Hegde during FOSSEE Fellowship 2018

1 files changed, 28 insertions, 9 deletions

diff --git a/macros/armcov.sci b/macros/armcov.sci
index 0c5158c..e36b4c7 100644
--- a/macros/armcov.sci
+++ b/macros/armcov.sci
@@ -1,22 +1,41 @@
-function [ar_coeff, var_est] = armcov(data_in, order)
-    
-    checkNArgin(2,2, argn(2));
+//Autoregressive all-pole model parameters — modified covariance method
+//Calling Sequence-
+//a = armcov(x,p)
+//[a,e] = armcov(x,p)
+//Parameters
+//x:input signal
+//p:order
+//a:output of an AR system driven by white noise
+//e:variance estimate
+//Description
+//This function uses the modified covariance method to fit a pth-order autoregressive (AR) model to the input signal x.
+
+//Example :
+//A = [1 -2.7607 3.8106 -2.6535 0.9238];
+//y = filter(1,A,0.2*rand(1024,1,"normal"));
+//arcoeffs = armcov(y,4)
+//OUTPUT :      // since "rand" function is used, output doesn't always remains same. It differs by some amount.
+//              1.  - 2.7450144    3.7762385  - 2.6201362     0.9104109    0.9104109
+
+    function [ar_coeff, var_est] = armcov(data_in, order)
+
+    checkNArgin(2,2, argn(2));                          // function call
     method = 'modified';
     [ar_coeff, var_est, msg] = arParEst(data_in, order, method);
     if ~isempty(msg) then
         error(msg);
     end
-    
-    
+
+
 endfunction
 
 function checkNArgin(min_argin, max_argin, num_of_argin)
     if num_of_argin < min_argin then
-        error('Not enough input arguments')
+        error('Not enough input arguments')     // Number of input arguments should be greater than min_argin
     end
-    
+
     if num_of_argin > max_argin then
-        error('Too many input arguments')
+        error('Too many input arguments')       // Number of input arguments should be lesserr than max_argin
     end
-        
+
 endfunction