From c0c0582462720ed597b00e116506570577614e89 Mon Sep 17 00:00:00 2001
From: shamikam
Date: Tue, 7 Nov 2017 15:59:48 +0530
Subject: initial commit

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 macros/taylorwin.sci~ | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 macros/taylorwin.sci~

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diff --git a/macros/taylorwin.sci~ b/macros/taylorwin.sci~
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+//Taylor Window
+TAYLORWIN(N) returns an N-point Taylor window in a column vector.
+//
+// TAYLORWIN(N,NBAR) returns an N-point Taylor window with NBAR nearly
+// constant-level sidelobes adjacent to the mainlobe. NBAR must be an
+// integer greater than or equal to one.
+//
+// TAYLORWIN(N,NBAR,SLL) returns an N-point Taylor window with SLL maximum
+// sidelobe level in dB relative to the mainlobe peak. SLL must be a
+// negative value, e.g., -30 dB.
+//
+//NBAR should satisfy NBAR >= 2*A^2+0.5, where A is equal to
+//acosh(10^(-SLL/20))/pi, otherwise the sidelobe level specified is not
+//guaranteed. If NBAR is not specified it defaults to 4. SLL defaults to
+//-30 dB if not specified.
+
+//Author: Parthasarathi Panda
+//parthasarathipanda314@gmail.com
+//the function is for application on vectors only
+//Modified function to reject negative window length and no of constant level sidelobes with appropriate error messages
+function [w]=taylorwin(n,nbar,sll)
+    [nargout,nargin]=argn();
+    if nargin<1 then
+        error("Not enough input arguments")
+    end
+    if nargin==1 then
+        nbar=4;
+        sll=-30;
+    elseif nargin==2
+        sll=-30;
+    end
+    if type(n)~=1 | type(nbar)~=1 | type(sll)~=1 then
+        error('check the data type of input'); //to check if the inputs are real/complex arrays
+    end
+    
+    if size(n)~=[1,1] then
+        error('check the data type of input'); //to check that n is single dimensional
+    end
+    if floor(n)~=n | imag(n)~=0 then
+        error('check that n is an integer');//to check if n is an integer
+    end
+    
+    if size(nbar)~=[1,1] then
+        error('check the data type of input'); //to check that nbar is single dimensional
+    end
+    if floor(nbar)~=nbar | imag(nbar)~=0 then
+        error('check that nbar is an integer');//to check if nbar is an integer
+    end
+    
+    if size(sll)~=[1,1] then
+        error('check the data type of input'); //to check that sll is single dimensional
+    end
+    if sll>0 | imag(sll)~=0 then
+        error('The sidelobe level SLL must be a negative number.');//to check if sll is a negative no.
+    end
+    //check if window length is positive
+    if(n<0) then
+        error("The window length must be a positive integer");
+    end
+    //check if no of constant level sidelobes is positive
+    if (nbar<=0) then
+        error("The number of nearly constant-level sidelobes NBAR must be a positive integer greater than 0.");
+    end
+    B=10^(-sll/20);
+    A=log(B+sqrt(B*B-1))/%pi;
+    sig=nbar*nbar/(A*A+(nbar-0.5)*(nbar-0.5));
+    //computing Fm (the coefficients for the cosines
+    m=ones(nbar-1,1)*[1:nbar-1];
+    i=([1:nbar-1])'*ones(1,nbar-1);
+    M=((1-((m.*m/sig)./(A*A+(i-0.5).*(i-0.5)))));//./(1-(m.*m)./(i.*i)));
+    m=[1:nbar-1];
+    F=prod(M,1).*((-1)^(m+1));
+    for m=1:nbar-1
+        j=[[1:m-1],[m+1:nbar-1]];
+        F(m)=F(m)/prod((1-(m.*m)./(j.*j)));
+    end
+    //computing the window
+    nv=ones(nbar-1,1)*([0:n-1]);
+    m=([1:nbar-1])'*ones(1,n);
+    M=cos(2*%pi*m.*(nv-(n-1)/2)/n);
+    w=ones(1,n)+F*M;
+    w=w';
+endfunction
-- 
cgit