idamnjanovic@10: %COLLINCOMB Linear combination of matrix columns.
idamnjanovic@10: %  Y = COLLINCOMB(A,COLS,X) computes a linear combination of the columns of
idamnjanovic@10: %  the matrix A. The column indices are specified in the vector COLS, and
idamnjanovic@10: %  the correspoinding coefficients are specified in the vector X. The
idamnjanovic@10: %  vectors COLS and X must be of the same length. 
idamnjanovic@10: %  
idamnjanovic@10: %  The call Y = COLLINCOMB(A,COLS,X) is essentially equivalent to
idamnjanovic@10: %
idamnjanovic@10: %         Y = A(:,COLS)*X .
idamnjanovic@10: %
idamnjanovic@10: %  However, it is implemented much more efficiently.
idamnjanovic@10: %
idamnjanovic@10: %  Y = COLLINCOMB(A,ROWS,COLS,X) only works on the rows of A specified
idamnjanovic@10: %  in ROWS, returning a vector of length equal to ROWS. This call is
idamnjanovic@10: %  essentially equivalent to the command
idamnjanovic@10: %
idamnjanovic@10: %         Y = A(ROWS,COLS)*X .
idamnjanovic@10: %
idamnjanovic@10: %  See also ROWLINCOMB.
idamnjanovic@10: 
idamnjanovic@10: 
idamnjanovic@10: %  Ron Rubinstein
idamnjanovic@10: %  Computer Science Department
idamnjanovic@10: %  Technion, Haifa 32000 Israel
idamnjanovic@10: %  ronrubin@cs
idamnjanovic@10: %
idamnjanovic@10: %  April 2009