1 files changed, 51 insertions, 0 deletions
diff --git a/armaX.sci b/armaX.sci
new file mode 100644
index 0000000..93376e2
--- /dev/null
+++ b/armaX.sci
@@ -0,0 +1,51 @@
+
+function sys = armaX(varargin)
+	[lhs , rhs] = argn();	
+	if ( rhs < 2 ) then
+			errmsg = msprintf(gettext("%s: Unexpected number of input arguments : %d provided while should be 2"), "armaX", rhs);
+			error(errmsg)
+	end
+
+	z = varargin(1)
+    if typeof(z) == 'iddata' then
+        Ts = z.Ts;unit = z.TimeUnit
+        z = [z.OutputData z.InputData]
+    elseif typeof(z) == 'constant' then
+        Ts = 1;unit = 'seconds'
+    end
+	if ((~size(z,2)==2) & (~size(z,1)==2)) then
+		errmsg = msprintf(gettext("%s: input and output data matrix should be of size (number of data)*2"), "armaX");
+		error(errmsg);
+	end
+
+	if (~isreal(z)) then
+		errmsg = msprintf(gettext("%s: input and output data matrix should be a real matrix"), "armaX");
+		error(errmsg);
+	end
+
+	n = varargin(2)
+	if (size(n,"*")<3| size(n,"*")>4) then
+		errmsg = msprintf(gettext("%s: The order and delay matrix [na nb nc nk] should be of size [3 or 4]"), "armaX");
+		error(errmsg);
+	end
+
+	if (size(find(n<0),"*") | size(find(((n-floor(n))<%eps)== %f))) then
+		errmsg = msprintf(gettext("%s: values of order and delay matrix [na nb nc nk] should be nonnegative integer number "), "armaX");
+		error(errmsg);
+	end
+
+	na = n(1); nb = n(2); nc = n(3); //nd = n(4);nf = n(5);
+	
+	if (size(n,"*") == 3) then
+		nk = 1
+	else
+		nk = n(4);
+	end
+
+    // storing U(k) , y(k) and n data in UDATA,YDATA and NDATA respectively 
+    YDATA = z(:,1);
+    UDATA = z(:,2);
+
+    sys = estpoly(z,[na,nb,nc,0,0,nk])
+    
+endfunction