function varargout=create_load_uniform(varargin)
%CREATE_LOAD_UNIFORM Create uniform traffic matrix for specified network.
% [TRAFFIC]=CREATE_LOAD_UNIFORM(METHOD,LOAD,NAME,NUMBER) is a script that
% creates traffic matrix for a sprcified network saved in a *.MAT file in
% MATLABROOT/networks/ directory. LOAD is the total offered load in the
% network, NAME is the 'NAME.mat' file stored in string that holds
% definition of the network, NUMBER is the structure number saved in the
% file according to STRUCTURE{:,:,NUMBER} [2] (for precise fields
% descriptionsee i.e. help CREATE_NETWORK).
%
% METHOD is the method used to make traffic matrix. Choosing 1 makes
% shortest paths (choosen randomly according to SHORTEST_PATH_DIJKSTRA
% function) between all node pairs. Load on every path is (LOAD)/(Number
% of paths). Method 2 uses algorithm described in [1] to choose shortest
% paths. Briefly saying, algorithm chooses paths between all node pairs,
% that have least adjacent links with other paths. Load on every path is
% computed just like in method 1.
%
% Result is saved in the NAME.mat file in the TRAFFIC field. If such
% field does not exists then script makes such one. If not then new
% traffic matrix is saved in the TRAFFIC field in NAME.mat file. Result
% can be also loaded to workspace.
%
% For example CREATE_LOAD_UNIFORM(1,13,'network',2) makes uniform load for
% STRUCTURE{:,:,2} definition saved in NETWORK.mat file in
% MATLABROOT/networks/ directory where total load in the network is 13
% Erlangs.
%
% See also CREATE_LOAD_MANUAL, CREATE_RAND_NETWORK, CREATE_NETWORK.
%
% References:
% [1] Przemyslaw Pawelczak, "Traffic Engineering in all-optical
% networks", M.Sc. thesis, Wroclaw University of Technology, Poland
% [2] T. E. Cormen et al., "Introduction to Algorithms",
% WNT, Warsaw 2000, page 527.
% Copyright 2003-2004 Przemyslaw Pawelczak
% E-mail: przemyslaw_pawelczak@idg.com.pl
% Wroclaw University of Technology, Poland
% $Revision: 1.0 $ $Date: 2004/02/20 12:40:16 $
%If no NUMBER specified then it will be first
if nargin==3
varargin{4}=1;
end
%Exeption handling
message=nargchk(3,4,nargin);
testing_int=[varargin{1},varargin{2},varargin{4}];
if ~isempty(message)
error('MATLAB:CREATE_LOAD_UNIFORM:NumberOfInputArguments',...
message);
end
if find(isnan(testing_int))
error('MATLAB:CREATE_LOAD_UNIFORM:ArgumentType',...
'Arguments must be numbers.');
end
%Check if VARARGIN are positive integers
if sum([testing_int<0,...
fix(varargin{1})~=varargin{1},...
fix(varargin{4})~=varargin{4},...
varargin{1}>2])~=0 %Only 2 choices
error('MATLAB:CREATE_LOAD_UNIFORM:ArgumentType',...
'Wrong type of argument.');
end
if ~isstr(varargin{3})
error('MATLAB:CREATE_LOAD_UNIFORM:ArgumentType',...
'Argument must be string.');
end
%Change string into number (for all number of arguments)
for k=[1,2,4]
if isstr(varargin{k})==1
varargin{k}=str2num(varargin{k});
end
end
%List all '*.mat' files in current working directory
%Change directory to MATLABROOT\networks - catalog must exist
cd([matlabroot,['\work\networks']]);
directory=what;
directory=struct2cell(directory);
directory=cellstr(directory{3});
%Check if specified '*.mat' file already exist
if find(strcmp(directory,[varargin{3},'.mat'])==1)
%Load *.MAT file
load(varargin{3});
fields_vector=[exist('description'),exist('structure')];
if length(find(fields_vector))~=2
error('MATLAB:CREATE_LOAD_UNIFORM:BadFieldNames',...
'Bad field names.');
end
%Check if TRAFFIC definition already exists in this file
%Initialize flag
load_exists=0;
varias=who;
varias_dimension=cellfun('ndims',varias);
varias_dimension=length(varias_dimension');
%Check
for k=1:varias_dimension
if isequal(cell2mat(varias(k)),'traffic')
load_exists=1;
end
end
%If definition does exist - add another
if load_exists==1
%Find how many different LOAD definitions are in this '*.mat' file
traffic_dimension=cellfun('ndims',traffic);
traffic_dimension=length(traffic_dimension(1,1,:))+1;
%Load MAKE_LOAD procedure
traffic=make_load(varargin{3},varargin{2},structure,traffic,varargin{4},traffic_dimension,varargin{1});
varargout{1}=save_network(description,structure,traffic,varargin{3});
%If definition does not exist - make first one
elseif load_exists==0;
traffic{1,1,1}=[];
%Load MAKE_LOAD procedure
traffic=make_load(varargin{3},varargin{2},structure,traffic,varargin{4},1,varargin{1});
varargout{1}=save_network(description,structure,traffic,varargin{3});
end
else
error('MATLAB:CREATE_LOAD_UNIFORM:BadFiledName',...
'Bad file name.');
end
function [traffic]=make_load(name,load,structure,traffic,structure_dimension,traffic_dimension,method)
%Data format: traffic{path number,path-1/load on path-2,number of dimensions (structures)};
%Check how many nodes are in the graph
struct_dim=cellfun('ndims',structure);
structure_length=length(struct_dim(:,1,1));
node_number=0;
for k=1:structure_length
if ~isempty(structure{k,1,structure_dimension})
node_number=node_number+1;
end
end
%Initialization of temporary traffic structure
%Pair of nodes for one direction
for k=1:(node_number^2/2-node_number)
%Pair of nodes for two directions
%for k=1:(node_number^2-node_number)
traffic_temp{k,1,1}=[];
traffic_temp{k,2,1}=[];
end
%Making vector of coordinates for paths (begin node - x, end node - y)
x_vector=[];
y_vector=[];
remove=[];
for k=1:node_number
x_vector=[x_vector,ones(1,node_number)+k-1];
y_vector=[y_vector,1:node_number];
%Pair of nodes for one direction
remove=[remove,((k-1)*node_number+1):(k+(k-1)*node_number)];
%Pair of nodes for two directions
%remove=[remove,(k+(k-1)*node_number)];
end
x_vector(remove)=[];
y_vector(remove)=[];
%Choose method for designing load and paths
switch method
case 1 %Random path, uniform load
%Computing paths and assignment to structure
for k=1:length(x_vector)
%Only shortest paths
traffic_temp{k,1,1}=shortest_path_dijkstra(x_vector(k),y_vector(k),name,structure_dimension);
traffic_temp{k,2,1}=load/length(x_vector);
end
%Procedure for adding traffic_temp to traffic
for k=1:length(x_vector)
traffic{k,1,traffic_dimension}=traffic_temp{k,1,1};
traffic{k,2,traffic_dimension}=traffic_temp{k,2,1};
end
case 2 %Optimal paths, uniform load
%Name every link in the graph with its number
link_matrix=ones(node_number,node_number);
link_wages=zeros(node_number,node_number);
link_positions=find(tril(link_matrix));
link_numbers=find(link_positions);
link_matrix(link_positions)=link_numbers;
link_matrix=tril(link_matrix)+triu(link_matrix',1);
%Assign wages to links
for k=1:length(x_vector)
%Only shortest paths - all shortest paths
all_paths=shortest_path_dijkstra_all(x_vector(k),y_vector(k),name,structure_dimension);
[row,column]=size(all_paths);
for f=1:row
for g=1:column-1
[sorted,sorted_positions]=sort([all_paths(f,g),all_paths(f,g+1)]);
link_wages(sorted(1),sorted(2))=link_wages(sorted(1),sorted(2))+1;
end
end
end
%Computing paths for the second time
for k=1:length(x_vector)
all_paths=shortest_path_dijkstra_all(x_vector(k),y_vector(k),name,structure_dimension);
[row,column]=size(all_paths);
wage_all_path(1:row)=0;
for f=1:row
for g=1:column-1
[sorted,sorted_positions]=sort([all_paths(f,g),all_paths(f,g+1)]);
wage_all_path(f)=wage_all_path(f)+link_wages(sorted(1),sorted(2));
end
end
[minimal,minimal_position]=min(wage_all_path);
traffic_temp{k,1,1}=all_paths(minimal_position,:);
traffic_temp{k,2,1}=load/length(x_vector);
end
%Procedure for adding traffic_temp to traffic
for k=1:length(x_vector)
traffic{k,1,traffic_dimension}=traffic_temp{k,1,1};
traffic{k,2,traffic_dimension}=traffic_temp{k,2,1};
end
end
function display_gap
disp(sprintf('\n'));
function [net_out]=save_network(description,structure,traffic,name)
save(name,'description','structure','traffic');
%Cannot make structure with cells of different dimension (sic!) - it needs
%checking
net_out=struct('traffic',traffic);
