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+//Convolution Matrix
+//convmtx(h,n) returns the convolution matrix for vector h. If h is a
+//column vector and X is a column vector of length n, then convmtx(h,n)*X
+//gives the result of the convolution oof h and X.If R is a row vector and X//is a row vector of length N, then X*convmtx(R,N) gives the convolution of R and X.
+//Example:
+//Generate a simple convolution matrix.
+//
+// h = [%i 1 2 3];
+// convmtx(h,7)       //Convolution matrix
+//
+//Author 
+//Debdeep Dey
+function t=convmtx(v,n);
+    n=double(n);
+    [mv,nv]=size(v);
+    v=v(:);
+    
+    //put Toeplitz code inline
+    c = [v; zeros(n-1,1)]; 
+    r = zeros(n,1);
+    m = length(c);
+    x = [r(n:-1:2) ; c(:)]; 
+    
+    cidx = (0:m-1)';
+        ridx = n:-1:1;
+    t = cidx(:,ones(n,1)) + ridx(ones(m,1),:); //Toeplitz subscripts
+    t(:) = x(t); //actual data
+    
+         //t = single(t);
+    // end of toeplitz code
+
+if mv < nv then
+    t = t.';
+    end
+    
+endfunction