1 files changed, 58 insertions, 36 deletions
diff --git a/macros/cheb2ap.sci b/macros/cheb2ap.sci
index 007d2d5..a599f31 100644
--- a/macros/cheb2ap.sci
+++ b/macros/cheb2ap.sci
@@ -1,39 +1,61 @@
-function [z, p, g] = cheb2ap (n, Rs)
-//This function designs a lowpass analog Chebyshev type II filter.
-//Calling Sequence
-//[z, p, g] = cheb2ap (n, Rs)
-//[z, p] = cheb2ap (n, Rs)
-//p = cheb2ap (n, Rs)
-//Parameters 
-//n: Filter Order
-//Rs: Stopband attenuation
-//z: Zeros
-//p: Poles
-//g: Gain
-//Description
-//This is an Octave function.
-//This function designs a lowpass analog Chebyshev type II filter of nth order and with a stopband attenuation of Rs.
-//Examples
+// Copyright (C) 2018 - IIT Bombay - FOSSEE
 //
+// This file must be used under the terms of the CeCILL.
+// This source file is licensed as described in the file COPYING, which
+// you should have received as part of this distribution.  The terms
+// are also available at
+// http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
+// Author:Sonu Sharma, RGIT Mumbai
+// Organization: FOSSEE, IIT Bombay
+// Email: toolbox@scilab.in
+
+function [z, p, g] = cheb2ap (n, Rs)
+    //This function produces a lowpass analog Chebyshev type II prototype filter.
+
+    //Calling Sequence
+    //[z, p, g] = cheb2ap (n, Rs)
+
+    //Parameters
+    //n: Filter Order
+    //Rs: Stopband attenuation (in dB)
+    //z: Zeros
+    //p: Poles
+    //g: Gain
+
+    //Description
+    //This function designs a lowpass analog Chebyshev type II filter of nth order and with a stopband attenuation of Rs.
+
+    //Examples
+    //[z, p, g] = cheb2ap (4, 10)
+    //Output :
+    // g  =
+    //
+    //    0.3162278
+    // p  =
+    //
+    //  - 0.1674887 + 0.9498949i
+    //  - 1.1818323 + 1.1499912i
+    //  - 1.1818323 - 1.1499912i
+    //  - 0.1674887 - 0.9498949i
+    // z  =
+    //
+    //  - 1.0823922i
+    //  - 2.6131259i
+    //    2.6131259i
+    //    1.0823922i
+
+
+    funcprot(0);
+    lhs = argn(1)
+    rhs = argn(2)
+    if (rhs < 2 | rhs > 2)
+        error("cheb2ap: Wrong number of input arguments.")
+    end
 
-funcprot(0);
-lhs = argn(1)
-rhs = argn(2)
-if (rhs < 2 | rhs > 2)
-error("Wrong number of input arguments.")
-end
-
-select(rhs)
-	
-	case 2 then
-		if(lhs==1)
-		z = callOctave("cheb2ap", n, Rs)
-		elseif(lhs==2)
-		[z, p] = callOctave("cheb2ap", n, Rs)
-		elseif(lhs==3)
-		[z, p, g] = callOctave("cheb2ap", n, Rs)
-		else
-		error("Wrong number of output argments.")
-		end
-	end
+    Rsf = 10 ^ (-Rs/20);    //stop band pick to pick ripple in fraction
+    rs = Rsf ;             //analpf function compitable stop band ripple (delta-s)
+    [hs,p,z,g]=analpf(n,"cheb2",[0 rs],1); //cutoff frequency of 1 rad/sec for prototype filter
+    p = p' ;
+    z = z' ;
+    g = abs(g);
 endfunction