1 files changed, 54 insertions, 43 deletions
diff --git a/macros/buttap.sci b/macros/buttap.sci
index 9c2e08d..f42141b 100644
--- a/macros/buttap.sci
+++ b/macros/buttap.sci
@@ -1,45 +1,56 @@
-function [z, p, g] = buttap (n)
-//Design a lowpass analog Butterworth filter.
-//Calling Sequence
-//z = buttap (n)
-//[z, p] = buttap (n)
-//[z, p, g] = buttap (n)
-//Parameters 
-//n: Filter Order
-//z: Zeros
-//p: Poles
-//g: Gain
-//Description
-//This is an Octave function.
-//It designs a lowpass analog Butterworth filter of nth order.
-//Examples
-//[z, p, g] = buttap (5)
-//z = [](0x0)
-//p =
-//
-//  -0.30902 + 0.95106i  -0.80902 + 0.58779i  -1.00000 + 0.00000i  -0.80902 - 0.58779i  -0.30902 - 0.95106i
+// Copyright (C) 2018 - IIT Bombay - FOSSEE
 //
-//g =  1
-
-
-funcprot(0);
-lhs = argn(1)
-rhs = argn(2)
-if (rhs < 1 | rhs > 1)
-error("Wrong number of input arguments.")
-end
-
-select(rhs)
-	
-	case 1 then
-		if(lhs==1)
-		z = callOctave("buttap",n)
-		elseif(lhs==2)
-		[z, p] = callOctave("buttap",n)
-		elseif(lhs==3)
-		[z, p, g] = callOctave("buttap",n)
-		else
-		error("Wrong number of output argments.")
-		end
-	end
+// 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] = buttap (n)
+    //Produces analog prototype Butterworth filter
+
+    //Calling Sequence
+    //[z, p, g] = buttap (n)
+
+    //Parameters
+    //n: Filter Order
+    //z: Zeros
+    //p: Poles
+    //g: Gain
+
+    //Description
+    //It gives a lowpass analog prototype Butterworth filter of nth order.
+
+    //Examples
+    //[z, p, g] = buttap(5)
+    //Output :
+    // g  =
+    //
+    //    1.
+    // p  =
+    //
+    //  - 0.3090170 - 0.9510565i
+    //  - 0.8090170 - 0.5877853i
+    //  - 1. - 1.225D-16i
+    //  - 0.8090170 + 0.5877853i
+    //  - 0.3090170 + 0.9510565i
+    // z  =
+    //
+    //     []
+
+
+    funcprot(0);
+    lhs = argn(1)
+    rhs = argn(2)
+    if (rhs < 1 | rhs > 1)
+        error("buttap: Wrong number of input arguments.")
+    end
+
+    [Hs, p, z, g] = analpf(n, "butt", [],1 );
+    p = p' ;
+    z = z' ;
+
 endfunction