The module "cell2sparse" of the Mastrave modelling library

Copyright and license notice of the function cell2sparse

Copyright © 2007,2008,2009,2010,2011 Daniele de Rigo

The file cell2sparse.m is part of Mastrave.

Mastrave is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Mastrave is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

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Function declaration

 sparse_vals = cell2sparse( cell_vals      ,
                            cell_rows = [] ,
                            siz       = [] )

Description

Utility to transform a numeric vector or cell-array of numeric vectors cell_vals into a sparse matrix sparse_vals . If cell_vals is a numeric vector then the corresponding returned sparse matrix has a single column whose nonzero elements are the vector elements. If cell_vals is a cell-array then the returned sparse matrix has a number of columns equal to the number of numeric vectors which compose as elements the cell-array. The row position of each nonzero element of sparse_vals is determined by the input argument cell_rows containing the row indices (subscripts) -- if omitted, the values of i-th numeric vector of cell_vals are remapped as nonzero elements of the i-th column of sparse_vals starting from the first row and occupying contiguous rows in the same column.

Input arguments

 cell_vals          ::cellnumeric,cell?same_rows::
                    Numeric vector or cell-array of numeric vectors.

 cell_rows          ::cellindex,cell?same_rows::
                    Vector of indices (or cell-array of indices vectors)
                    representing the row position of the corresponding
                    elements of  cell_vals .
                    If it is an empty array  [] , each numeric vector
                    of  cell_vals  is remapped to fill the corresponding
                    column of  sparse_vals  starting from the first row
                    and occupying contiguous rows in the same column.
                    If omitted, the default value is  [] .

 siz                ::numel,2-vector::
                    Size of the returned sparse matrix  sparse_vals .
                    If it is an empty array  [] , the size is computed
                    as the minimum one able to contain all the passed
                    values.
                    If omitted, the default value is  [] .

Example of usage

   vnum      = [ 1 5 4 8 3 ]

   lens      = [ 3 0 4 3 0 0 9 0]
   N         = sum( lens )
   vcell     = mat2cell( 10*[1:N] , 1 , lens )
   cell_rows = mat2cell(    [1:N] , 1 , lens )

   cell2sparse( vnum )
   full( cell2sparse( vcell ) )

   % Passing the row position of each element
   full( cell2sparse( vcell , cell_rows ) )

   % Passing the size of  sparse_vals 
   full( cell2sparse( vcell , []        , [15,10] ) )
   full( cell2sparse( vcell , cell_rows , [25,10] ) )

See also:
   cellstr2index, get_cell_elem, mat2groups



Keywords:
   conversion, cell-array, sparse-matrix



Version: 0.3.2

Support

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