1 files changed, 35 insertions, 32 deletions
diff --git a/macros/blackmanharris.sci b/macros/blackmanharris.sci
index f2affdf..faec39a 100644
--- a/macros/blackmanharris.sci
+++ b/macros/blackmanharris.sci
@@ -1,35 +1,38 @@
 function w = blackmanharris (m, opt)
-//This function returns the filter coefficients of a Blackman-Harris window.
-//Calling Sequence
-//w = blackmanharris (m)
-//w = blackmanharris (m, opt)
-//Parameters 
-//m: positive integer value
-//opt: string value, takes "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 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
-//blackmanharris(5,"periodic")
-//ans  =
-//    0.00006    
-//    0.1030115  
-//    0.7938335  
-//    0.7938335  
-//    0.1030115  
- 
-rhs = argn(2)
-if(rhs<1 | rhs>2)
-error("Wrong number of input arguments.")
-end
 
-	select(rhs)
-	case 1 then
-	w = callOctave("blackmanharris",m)
-	case 2 then
-	w = callOctave("blackmanharris",m,opt)
-	end
-endfunction
+ funcprot(0);
+    rhs= argn(2);
+
+  if (rhs < 1 | rhs > 2)
+     error("Wrong Number of input arguments");
+  end
+
+  if (~ (isscalar (m) & (m == fix (m)) & (m > 0)))
+    error ("blackmanharris: M must be a positive integer");
+  end
+
+  N = m - 1;
+  if (rhs == 2)
+    select (opt)
+      case "periodic"
+        N = m;
+      case "symmetric"
+        N = m-1;
+      else
+        error ("blackmanharris: window type must be either periodic or symmetric");
+    end
+  end
 
+
+  if (m == 1)
+    w = 1;
+  else
+    a0 = 0.35875;
+    a1 = 0.48829;
+    a2 = 0.14128;
+    a3 = 0.01168;
+    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