code by jitendra

1 files changed, 47 insertions, 14 deletions

diff --git a/macros/cceps.sci b/macros/cceps.sci
index 3756a5d..f026256 100644
--- a/macros/cceps.sci
+++ b/macros/cceps.sci
@@ -5,26 +5,59 @@ function y = cceps (x,correct)
 //cceps(x, correct)
 //Parameters
 //x: vector.
-//correct: if 1, a correction method  is applied.
+//correct: if 1, a correction method is applied.
 //Description
 //This function return the complex cepstrum of the vector x. If the optional argument correct has the value 1, a correction method is applied. The default is not to do this.
 //Examples
 //cceps([1,2,3],1)
-//ans = 
-//     1.92565
-//     0.96346
-//    -1.09735
+//ans = 1.9256506  
+ //   0.9634573  
+//  - 1.0973484 
 
-funcprot(0);
-rhs = argn(2)
-if(rhs<1 | rhs>2)
+if(argn(2)<1 | argn(2)>2)
 error("Wrong number of input arguments.")
 end
+ if argn(2)==1 then
+ correct=0;
+end
+
+ [r, c]=size(x)         
+     if (c ~= 1)
+    if (r == 1)
+      x = x;
+      r = c;
+    else
+      error ("x must be a vector");
+    end
+  end
+  
+        F = fft1(x);  
+      if (min (abs (F)) == 0)
+    error ('bad signal x, some Fourier coefficients are zero.');
+  end 
+ h = fix (r / 2);
+  cor = 0;
+  if (2 * h == r)
+    cor = (c & (real (F (h + 1)) < 0));
+    if (cor)
+      F = fft1 (x(1:r-1))
+      if (min (abs (F)) == 0)
+        error ('bad signal x, some Fourier coefficients are zero.');
+      end
+    end
+  end
+  y = fftshift1 (ifft1 ((log (F))'));
+
+  //## make result real
+  if (c)
+    y = real (y);
+    if (cor)
+     // ## make cepstrum of same length as input vector
+      y (r) = 0;
+    end
+  end
+    
 
-	select(rhs)
-	case 1 then
-	y = callOctave("cceps",x)
-	case 2 then
-	y = callOctave("cceps",x,correct)
-	end
 endfunction
+
+