1 files changed, 36 insertions, 10 deletions
diff --git a/macros/periodogram.sci b/macros/periodogram.sci
index 33e15af..ca8995e 100755
--- a/macros/periodogram.sci
+++ b/macros/periodogram.sci
@@ -1,20 +1,46 @@
 function [d,n]=periodogram(a,b,c,d,e)
+//Return the periodogram (Power Spectral Density) of X
+//Calling Sequence
+// [PXX, W] = periodogram (X)
+// [PXX, W] = periodogram (X, WIN)
+// [PXX, W] = periodogram (X, WIN, NFFT)
+// [PXX, W] = periodogram (X, WIN, NFFT, FS)
+// [PXX, W] = periodogram (..., "RANGE")
+//Parameters 
+// X:data vector.  If X is real-valued a one-sided spectrum is estimated. If X is complex-valued, or "RANGE" specifies "twosided", the full spectrum is estimated.
+//WIN: window weight data.  If window is empty or unspecified a default rectangular window is used.  Otherwise, the window is applied to the signal ('X .* WIN') before computing th periodogram.  The window data must be a vector of the same length as X.
+//NFFT:number of frequency bins.  The default is 256 or the next higher power of 2 greater than the length of X ('max (256,2.^nextpow2 (length (x)))').  If NFFT is greater than the length of the input then X will be zero-padded to the length of NFFT.
+//FS:sampling rate.  The default is 1.
+//RANGE:range of spectrum.  "onesided" computes spectrum from [0..nfft/2+1]."twosided" computes spectrum from [0..nfft-1].
+//Description
+//The optional second output W are the normalized angular frequencies.  For a one-sided calculation W is in the range [0, pi]. If NFFT is even and [0, pi) if NFFT is odd.  Similarly, for a two-sided calculation W is in the range [0, 2*pi] or [0, 2*pi)depending on NFFT.
+//
+//If a sampling frequency is specified, FS, then the output frequencies F will be in the range [0, FS/2] or [0, FS/2) for one-sided calculations. For two-sided calculations the range will be [0, FS).
+//
+//When called with no outputs the periodogram is immediately plotted in the current figure window.
     funcprot(0);
-    [nargout,nargin]=argn();
-    select nargin
+    lhs= argn(1);
+    rhs= argn(2);
+    if(rhs<1 | rhs>5)
+        error("Wrong number of input arguments");
+    end
+    if(lhs>2 | lhs< 2)
+        error("Wrong number of output arguments");
+    end
+    select(rhs)
     case 1 then
-        [d,n]=callOctave('periodogram',a);
+            [d,n]= callOctave('periodogram',a);
     case 2 then
-        [d,n]=callOctave('periodogram',a,b);
+            [d,n]= callOctave('periodogram',a,b);
+
     case 3 then
-        [d,n]=callOctave('periodogram',a,b,c);
+            [d,n]= callOctave('periodogram',a,b,c);
+
     case 4 then
-        [d,n]=callOctave('periodogram',a,b,c,d);  
+            [d,n]= callOctave('periodogram',a,b,c,d);
+  
     case 5 then
-        [d,n]=callOctave('periodogram',a,b,c,d,e);    
-    else
-        error("Incorrect no. of Input Arguments");
+            [d,n]= callOctave('periodogram',a,b,c,d,e);
     end
-
 endfunction