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+function w=blackman(N,sflag)
+//Generates a Blackman window
+//Calling Sequence
+//w=blackman(N)
+//w=blackman(N,sflag)
+//Parameters
+//N
+//A positive integer describing the length of the blackman window
+//sflag
+//Specifies the type of blackman window desired. Can be 'symmetric' or 'periodic'
+//Description
+//w=blackman(N) returns an N-point symmetric Blackman window in a column vector w
+//w=blackman(N,sflag)
+//Returns an N point Blackman window using the type of sampling specified by sflag
+//sflag can be either 'symmetric' (default) or 'periodic' (used in spectral analysis)
+//Example
+//w=blackman(4)
+//w  =
+// 
+//  - 1.388D-17  
+//    0.63       
+//    0.63       
+//  - 1.388D-17  
+//Author
+//Ankur Mallick
+//References
+//[1] Oppenheim, Alan V., Ronald W. Schafer, and John R. Buck. Discrete-Time Signal Processing. Upper Saddle River, NJ: Prentice Hall, 1999.
+    funcprot(0);
+    if(argn(2)<2)
+        sflag='symmetric'; //Default
+    end
+    if(argn(2)<1|argn(2)>2)
+        error('Incorrect number of input arguments.');
+    elseif(~isscalar(N)|N<=0|round(N)~=N)
+        error('N must be a positive integer')
+    elseif(sflag~='symmetric'&sflag~='periodic')
+        error('Sampling flag must be either symmetric or periodic');
+    elseif(N==1)
+        w=1; //Trivial case
+    else
+        flag=0;
+        if(sflag=='periodic')
+            N=N+1;
+            flag=1;
+        end
+        if(pmodulo(N,2)==1)
+            M=(N+1)/2; //odd
+        else
+            M=N/2; //even
+        end
+        n=0:1:M-1;
+        w1=0.42-0.5*cos(2*%pi*n/(N-1))+0.08*cos(4*%pi*n/(N-1));
+        p=2*M-N; //0 for N even, 1 for N odd
+        w=[w1, w1(M-p:-1:1)]';
+        if(flag==1)
+            //Periodic case
+            w(N)=[];
+        end
+    end
+endfunction