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Scripts_Sharing/ISFC/Utils_Graphs/gspbox/graphs/gsp_graph_default_parameters.m
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gsp_graph_default_parameters.m
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function G = gsp_graph_default_parameters(G)
%GSP_GRAPH_DEFAULT_PARAMETERS load default parameters for graphs
% Usage: G = gsp_graph_default_parameters(G);
% G = gsp_graph_default_parameters();
%
% Input parameters
% G : Graph (Optional)
% Output parameters
% G : Graph
%
% This function will fill a graph with all missing parameters such that
% it is compabatible with all functions of the GSPBox. If you create a
% graph manually, you need to set only the weight matrix W. If you have
% some coordonate, you can also set G.coords. G.coords is a N x 2
% or a N x 3 matrix with each columns beeing the coordonates in each
% dimention. Finally, we recommend to set the fiel G.type with a name
% that suits your graph.
%
% Example:
%
% W = rand(30);
% W = (W + W')/2;
% G.W = W - diag(diag(W));
% G = gsp_graph_default_parameters(G)
%
% This function can be used to update the weights of your graph. It will
% recompute the Laplacian operator. Warning this function does not
% perform any change to the Fourier basis:
%
% G.W = Wnew;
% G = gsp_graph_default_parameters(G);
%
%
% List of parameters of the graph structure
% -----------------------------------------
%
% By default, a graph structure in the GSPbox contains the following
% parameters:
%
% G.W*: Weight matrix (empty by default)
% G.A*: Adacency matrix (constructed with W*)
% G.N*: Number of nodes (size(W,1))
% G.type*: Type of graph ('unknown' by default)
% G.directed*: 1 if the graph is directed, 0 if not
% G.lap_type*: Laplacian type (default 'combinatorial') See the
% function GSP_CREATE_LAPLACIAN for a exhaustive list of the
% available laplacians.
% G.d*: Degree vector (Computed with G.W*)
% G.Ne*: Number of edges
% G.coords*: Coordinates of the vertices (default (0,0) )
% G.plotting*: Plotting parameters
% G.plotting.edge_width*: Width of edges (default 1)
% G.plotting.edge_color*: Color of edges (default [255,88,41]/255 )
% G.plotting.edge_style*: Style of edges (default '-')
% G.plotting.vertex_size*: Size of vertex (default 50)
% G.plotting.vertex_color*: Color of vertex (default 'b')
%
% Remark: There is redudancy between A, W, L. However, the GSPBox
% is done in matlab and is not suppose yet to scale to graph sufficiently
% large that your matlab have memory problem. However, this will be most
% likely change for milestone 1.0.0. If you do have a urgent need to
% overcome this problem, please contact the devolper team.
%
%
% Url: http://lts2research.epfl.ch/gsp/doc/graphs/gsp_graph_default_parameters.php
% Copyright (C) 2013-2016 Nathanael Perraudin, Johan Paratte, David I Shuman.
% This file is part of GSPbox version 0.5.2
%
% This program 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.
%
% This program 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.
%
% You should have received a copy of the GNU General Public License
% along with this program. If not, see <http://www.gnu.org/licenses/>.
% If you use this toolbox please kindly cite
% N. Perraudin, J. Paratte, D. Shuman, V. Kalofolias, P. Vandergheynst,
% and D. K. Hammond. GSPBOX: A toolbox for signal processing on graphs.
% ArXiv e-prints, Aug. 2014.
% http://arxiv.org/abs/1408.5781
% Author: Nathanael Perraudin
% Date : 09.12.2013
if nargin<1
G=struct;
end
if ~isfield(G,'W') % Weight matrix
G.W = sparse(0);
end
G.A=sparse(G.W>0);
G.N = size(G.W,1);
% Type of graph
if ~isfield(G,'type')
G.type='unknown';
end;
if ~isfield(G,'directed')
G.directed = gsp_isdirected(G);
end;
if ~isfield(G,'hypergraph')
G.hypergraph = 0;
end;
% Create the graph Laplacian
if ~isfield(G,'lap_type')
G.lap_type='combinatorial';
end
% if ~isfield(G,'L')
G = gsp_create_laplacian(G);
% end
G.d = sum(G.W,2);
% Number of edges
if G.directed
G.Ne = nnz(G.W);
else
G.Ne = nnz(G.W)/2;
end
if ~isfield(G,'coords') % Coordonates
G.coords = [];
end
G = gsp_graph_default_plotting_parameters(G);
end
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