Implement cceps.sci in Scilab

1 files changed, 52 insertions, 40 deletions

diff --git a/macros/cceps.sci b/macros/cceps.sci
index f026256..b87d4bf 100644
--- a/macros/cceps.sci
+++ b/macros/cceps.sci
@@ -1,63 +1,75 @@
-function y = cceps (x,correct)
-//Return the complex cepstrum of the vector x
-//Calling Sequence
+function y = cceps(x, correct)
+//Return the complex cepstrum of the vector x.
+//Calling Sequence:
 //cceps (x)
 //cceps(x, correct)
-//Parameters
-//x: vector.
-//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 = 1.9256506  
- //   0.9634573  
-//  - 1.0973484 
-
-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)
+//Parameters:
+//x: vector
+//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 = 1.9256506
+//      0.9634573
+//     -1.0973484
+
+  if(argn(2) < 1 | argn(2) > 2)
+    error("Wrong number of input arguments.");
+  end
+
+  if (argn(2) == 1)
+    correct = 0;
+  end
+
+  [r, c] = size(x);
+  if (c ~= 1)
     if (r == 1)
-      x = x;
+      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.');
+
+  F = fft(x);  
+  if (min(abs(F)) == 0)
+    error('bad signal x, some Fourier coefficients are zero.');
   end 
- h = fix (r / 2);
+
+  h = fix (r / 2);
   cor = 0;
-  if (2 * h == r)
-    cor = (c & (real (F (h + 1)) < 0));
+  if (2*h == r)
+    cor = (correct & (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.');
+      F = fft(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))'));
+  y = fftshift(ifft((log (F))));
 
-  //## make result real
-  if (c)
-    y = real (y);
+  if (correct)
+    y = real(y);
     if (cor)
-     // ## make cepstrum of same length as input vector
       y (r) = 0;
     end
   end
-    
 
 endfunction
 
+//input validation:
+//assert_checkerror("cceps()", "Wrong number of input arguments.");
+//assert_checkerror("cceps(1, 2, 3)", "Wrong number of input arguments.");
+//assert_checkerror("cceps([1, 2; 3, 4])", "x must be a vector");
+//assert_checkerror("cceps(0)", 'bad signal x, some Fourier coefficients are zero.');
+//assert_checkerror("cceps(zeros(10, 1))", 'bad signal x, some Fourier coefficients are zero.');
 
+//tests:
+//assert_checkalmostequal(cceps([1, 2, 3]), [1.9257; 0.9635; -1.0973], 0.5*10^-4);
+//assert_checkequal(cceps([1, 2, 3]), cceps([1, 2, 3], 1));
+//assert_checkequal(cceps([-1, -2, -3]), cceps([-1; -2; -3]));
+//assert_checkalmostequal(cceps([1+2*%i; -2-2*%i; -3+2*%i]), [0.4734+1.1174*%i; 1.2144+1.5358*%i; -0.1899+0.0247*%i], 5*10^-3);
+//assert_checkalmostequal(cceps([1+2*%i; -2-2*%i; -3+2*%i], 1), [0.4734; 1.2144; -0.1899], 5*10^-4);