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add qgsgraphanalyzer.*

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Sergey Yakushevs
Sergey Yakushevs committed May 25, 2011
1 parent b7946b4 commit 8560e4d47fcb0f5c8b97ac7ac6dea1d239ecbb19
@@ -8,11 +8,13 @@ SET(QGIS_NETWORK_ANALYSIS_SRCS
qgsgraphbuilder.cpp
qgsdistanceedgeproperter.cpp
qgslinevectorlayerdirector.cpp
qgsgraphanalyzer.cpp
)

INCLUDE_DIRECTORIES(BEFORE raster)

SET(QGIS_ANALYSIS_MOC_HDRS
qgslinevectorlayerdirector.cpp
)

QT4_WRAP_CPP(QGIS_NETWORK_ANALYSIS_MOC_SRCS ${QGIS_ANALYSIS_MOC_HDRS})
@@ -58,7 +60,8 @@ SET(QGIS_NETWORK_ANALYSIS_HDRS
qgsedgeproperter.h
qgsdistanceedgeproperter.h
qgsgraphdirector.h
qgslinevectorlayerdirector.h )
qgslinevectorlayerdirector.h
qgsgraphanalyzer.h )

INSTALL(CODE "MESSAGE(\"Installing NETWORK ANALYSIS headers...\")")
INSTALL(FILES ${QGIS_NETWORK_ANALYSIS_HDRS} ${QGIS_NETWORK_ANALYSIS_MOC_HDRS} DESTINATION ${QGIS_INCLUDE_DIR})
@@ -0,0 +1,103 @@
/***************************************************************************
qgsgraphanlyzer.cpp - QGIS Tools for graph analysis
-------------------
begin : 14 april 2011
copyright : (C) Sergey Yakushev
email : Yakushevs@list.ru
***************************************************************************/

/***************************************************************************
* *
* 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 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
// C++ standart includes
#include <limits>

// QT includes
#include <QMap>
#include <QVector>
#include <QPair>

//QGIS-uncludes
#include "qgsgraph.h"
#include "qgsgraphanalyzer.h"

void QgsGraphAnalyzer::shortestpath( const QgsGraph* source, int startPointIdx, int criterionNum, const QVector<int>& destPointCost, QVector<double>& cost, QgsGraph* treeResult )
{

// QMap< cost, vertexIdx > not_begin
// I use it and not create any struct or class.
QMap< double, int > not_begin;
QMap< double, int >::iterator it;

// QVector< QPair< cost, edge id > result
QVector< QPair< double, int > > result;

result.reserve( source->vertexCount() );
int i;
for ( i=0; i < source->vertexCount(); ++i )
{
result.push_back( QPair<double, int> ( std::numeric_limits<double>::infinity() , i ) );
}
result.push_back ( QPair<double, int>( 0.0, -1 ) );

not_begin.insert( 0.0, startPointIdx );

// begin Dijkstra algorithm
while ( !not_begin.empty() )
{
it = not_begin.begin();
double curCost = it.key();
int curVertex = it.value();
not_begin.erase( it );

QgsGraphEdgeList l = source->vertex( curVertex ).outEdges();
QgsGraphEdgeList::iterator edgeIt;
for (edgeIt = l.begin(); edgeIt != l.end(); ++edgeIt)
{
const QgsGraphEdge& edge = source->edge( *edgeIt );
double cost = edge.property( criterionNum ).toDouble() + curCost;

if ( cost < result[ edge.in() ].first )
{
result[ edge.in() ] = QPair< double, int >( cost, *edgeIt );
not_begin.insert( cost, edge.in() );
}
}
}

// fill shortestpath tree
if ( treeResult != NULL )
{
// sourceVertexIdx2resultVertexIdx
QVector<int> source2result( result.size(), -1 );

for ( i=0; i < source->vertexCount(); ++i )
{
if ( result[ i ].first < std::numeric_limits<double>::infinity() )
{
source2result[ i ] = treeResult->addVertex( source->vertex(i).point() );
}
}
for ( i=0; i < source->vertexCount(); ++i )
{
if ( result[ i ].first < std::numeric_limits<double>::infinity() && result[i].second != -1)
{
const QgsGraphEdge& edge = source->edge( result[i].second );

treeResult->addEdge( source2result[ edge.out() ], source2result[ i ],
edge.properties() );
}
}
}

// fill shortestpath's costs
for ( i=0; i < destPointCost.size(); ++i )
{
cost[i] = result[ destPointCost[i] ].first;
}
}
@@ -0,0 +1,46 @@
/***************************************************************************
qgsgraphalyzer.h - QGIS Tools for vector geometry analysis
-------------------
begin : 14 april 2010
copyright : (C) Sergey Yakushev
email : yakushevs@list.ru
***************************************************************************/

/***************************************************************************
* *
* 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 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/

#ifndef QGSGRAPHANALYZERH
#define QGSGRAPHANALYZERH

//QT-includes
#include <QVector>

// forward-declaration
class QgsGraph;

/** \ingroup analysis
* The QGis class provides graph analysis functions
*/

class QgsGraphAnalyzer
{
public:
/**
* solve shortest path problem using dijkstra algorithm
* @param source The source graph
* @param startVertexIdx index of start vertex
* @param criterionNum index of edge property as optimization criterion
* @param destPointCost array of vertex indexes. Function calculating shortest path costs for vertices with these indexes
* @param cost array of cost paths
* @param treeResult return shortest path tree
*/
static void shortestpath( const QgsGraph* source, int startVertexIdx, int criterionNum, const QVector<int>& destPointCost, QVector<double>& cost, QgsGraph* treeResult );

};
#endif //QGSGRAPHANALYZERH

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