1 files changed, 33 insertions, 28 deletions
diff --git a/macros/nuttallwin.sci b/macros/nuttallwin.sci
index c066ef5..a7090ad 100644
--- a/macros/nuttallwin.sci
+++ b/macros/nuttallwin.sci
@@ -1,34 +1,39 @@
 function w = nuttallwin (m, opt)
-//This function returns the filter coefficients of a Blackman-Harris window.
-//Calling Sequence
-//w = nuttallwin (m)
-//w = nuttallwin (m, opt)
-//Parameters 
-//m: positive integer value
-//opt: string value, takes in "periodic" or "symmetric"
-//w: output variable, vector of real numbers 
-//Description
-//This is an Octave function.
-//This function returns the filter coefficients of a Blackman-Harris window defined by Nuttall of length m supplied as input, to the output vector w.
-//The second parameter can take the values "periodic" or "symmetric", depending on which the corresponding form of window is returned. The default is symmetric.
-//Examples
-//nuttallwin(2, "periodic")
-//ans  =
-//  - 2.429D-17  
-//    1.    
 
+ funcprot(0);
+    rhs= argn(2);
 
+  if (rhs < 1 | rhs > 2)
+     error("Wrong Number of input arguments");
+  end
 
-rhs = argn(2)
-if(rhs<1 | rhs>2)
-error("Wrong number of input arguments.")
-end
+  if (~ (isscalar (m) & (m == fix (m)) & (m > 0)))
+    error ("nuttallwin: M must be a positive integer");
+  end
 
-	select(rhs)
-	case 1 then
-	w = callOctave("nuttallwin",m)
-	case 2 then
-	w = callOctave("nuttallwin",m,opt)
-	end
-endfunction
+  N = m - 1;
+  if (rhs == 2)
+    select (opt)
+      case "periodic"
+        N = m;
+      case "symmetric"
+        N = m-1;
+      else
+        error ('nuttallwin: window type must be either periodic or symmetric");
+    end
+  end
+
+    if (m == 1)
+        w = 1;
+    else
+        a0 = 0.355768;
+        a1 = 0.487396;
+        a2 = 0.144232;
+        a3 = 0.012604;
+//        n = [-N/2:(m-1)/2]';
+//        w = a0 + a1.*cos(2.*%pi.*n./N) + a2.*cos(4.*%pi.*n./N) + a3.*cos(6.*%pi.*n./N);
+        n=[0:m-1]'
+        w = a0 - a1.*cos(2.*%pi.*n./N) + a2.*cos(4.*%pi.*n./N) - a3.*cos(6.*%pi.*n./N);
+     end
 
+endfunction