25QString QgsJoinWithLinesAlgorithm::name()
const
27 return QStringLiteral(
"hublines" );
30QString QgsJoinWithLinesAlgorithm::displayName()
const
32 return QObject::tr(
"Join by lines (hub lines)" );
35QStringList QgsJoinWithLinesAlgorithm::tags()
const
37 return QObject::tr(
"join,connect,lines,points,hub,spoke,geodesic,great,circle" ).split(
',' );
40QString QgsJoinWithLinesAlgorithm::group()
const
42 return QObject::tr(
"Vector analysis" );
45QString QgsJoinWithLinesAlgorithm::groupId()
const
47 return QStringLiteral(
"vectoranalysis" );
50void QgsJoinWithLinesAlgorithm::initAlgorithm(
const QVariantMap & )
53 QObject::tr(
"Hub layer" ) ) );
55 QObject::tr(
"Hub ID field" ), QVariant(), QStringLiteral(
"HUBS" ) ) );
58 QObject::tr(
"Hub layer fields to copy (leave empty to copy all fields)" ),
63 QObject::tr(
"Spoke layer" ) ) );
65 QObject::tr(
"Spoke ID field" ), QVariant(), QStringLiteral(
"SPOKES" ) ) );
68 QObject::tr(
"Spoke layer fields to copy (leave empty to copy all fields)" ),
74 auto distanceParam = std::make_unique< QgsProcessingParameterDistance >( QStringLiteral(
"GEODESIC_DISTANCE" ), QObject::tr(
"Distance between vertices (geodesic lines only)" ), 1000 );
77 distanceParam->setIsDynamic(
true );
79 distanceParam->setDynamicLayerParameterName( QStringLiteral(
"HUBS" ) );
80 addParameter( distanceParam.release() );
82 auto breakParam = std::make_unique< QgsProcessingParameterBoolean >( QStringLiteral(
"ANTIMERIDIAN_SPLIT" ), QObject::tr(
"Split lines at antimeridian (±180 degrees longitude)" ),
false );
84 addParameter( breakParam.release() );
89QString QgsJoinWithLinesAlgorithm::shortHelpString()
const
91 return QObject::tr(
"This algorithm creates hub and spoke diagrams by connecting lines from points on the Spoke layer to matching points in the Hub layer.\n\n"
92 "Determination of which hub goes with each point is based on a match between the Hub ID field on the hub points and the Spoke ID field on the spoke points.\n\n"
93 "If input layers are not point layers, a point on the surface of the geometries will be taken as the connecting location.\n\n"
94 "Optionally, geodesic lines can be created, which represent the shortest path on the surface of an ellipsoid. When "
95 "geodesic mode is used, it is possible to split the created lines at the antimeridian (±180 degrees longitude), which can improve "
96 "rendering of the lines. Additionally, the distance between vertices can be specified. A smaller distance results in a denser, more "
100QString QgsJoinWithLinesAlgorithm::shortDescription()
const
102 return QObject::tr(
"Creates lines joining two point layers, based on a common attribute value." );
105QgsJoinWithLinesAlgorithm *QgsJoinWithLinesAlgorithm::createInstance()
const
107 return new QgsJoinWithLinesAlgorithm();
112 if ( parameters.value( QStringLiteral(
"SPOKES" ) ) == parameters.value( QStringLiteral(
"HUBS" ) ) )
115 std::unique_ptr< QgsProcessingFeatureSource > hubSource( parameterAsSource( parameters, QStringLiteral(
"HUBS" ), context ) );
119 std::unique_ptr< QgsProcessingFeatureSource > spokeSource( parameterAsSource( parameters, QStringLiteral(
"SPOKES" ), context ) );
123 const QString fieldHubName = parameterAsString( parameters, QStringLiteral(
"HUB_FIELD" ), context );
124 const int fieldHubIndex = hubSource->fields().lookupField( fieldHubName );
125 const QStringList hubFieldsToCopy = parameterAsStrings( parameters, QStringLiteral(
"HUB_FIELDS" ), context );
127 const QString fieldSpokeName = parameterAsString( parameters, QStringLiteral(
"SPOKE_FIELD" ), context );
128 const int fieldSpokeIndex = spokeSource->fields().lookupField( fieldSpokeName );
129 const QStringList spokeFieldsToCopy = parameterAsStrings( parameters, QStringLiteral(
"SPOKE_FIELDS" ), context );
131 if ( fieldHubIndex < 0 || fieldSpokeIndex < 0 )
134 const bool geodesic = parameterAsBoolean( parameters, QStringLiteral(
"GEODESIC" ), context );
135 const double geodesicDistance = parameterAsDouble( parameters, QStringLiteral(
"GEODESIC_DISTANCE" ), context ) * 1000;
137 QgsExpressionContext expressionContext = createExpressionContext( parameters, context, hubSource.get() );
139 if ( dynamicGeodesicDistance )
141 geodesicDistanceProperty = parameters.
value( QStringLiteral(
"GEODESIC_DISTANCE" ) ).value<
QgsProperty >();
144 const bool splitAntimeridian = parameterAsBoolean( parameters, QStringLiteral(
"ANTIMERIDIAN_SPLIT" ), context );
151 if ( hubFieldsToCopy.empty() )
153 hubOutFields = hubSource->fields();
154 hubFieldIndices.reserve( hubOutFields.
count() );
155 for (
int i = 0; i < hubOutFields.
count(); ++i )
157 hubFieldIndices << i;
162 hubFieldIndices.reserve( hubOutFields.
count() );
163 for (
const QString &field : hubFieldsToCopy )
165 const int index = hubSource->fields().
lookupField( field );
168 hubFieldIndices << index;
169 hubOutFields.
append( hubSource->fields().at( index ) );
175 hubFields2Fetch << fieldHubIndex;
179 if ( spokeFieldsToCopy.empty() )
181 spokeOutFields = spokeSource->fields();
182 spokeFieldIndices.reserve( spokeOutFields.
count() );
183 for (
int i = 0; i < spokeOutFields.
count(); ++i )
185 spokeFieldIndices << i;
190 for (
const QString &field : spokeFieldsToCopy )
192 const int index = spokeSource->fields().
lookupField( field );
195 spokeFieldIndices << index;
196 spokeOutFields.
append( spokeSource->fields().at( index ) );
202 spokeFields2Fetch << fieldSpokeIndex;
222 std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral(
"OUTPUT" ), context, dest, fields,
231 p = *
static_cast< const QgsPoint *
>( feature.geometry().constGet() );
233 p = *
static_cast< const QgsPoint *
>( feature.geometry().pointOnSurface().constGet() );
234 if ( hasZ && !p.
is3D() )
242 const double step = hubSource->featureCount() > 0 ? 100.0 / hubSource->featureCount() : 1;
258 const QgsPoint hubPoint = getPointFromFeature( hubFeature );
262 for (
int j = 0; j < hubFeature.
attributes().count(); ++j )
264 if ( !hubFieldIndices.contains( j ) )
266 hubAttributes << hubFeature.
attribute( j );
275 while ( spokeFeatures.
nextFeature( spokeFeature ) )
284 const QgsPoint spokePoint = getPointFromFeature( spokeFeature );
289 if ( splitAntimeridian )
294 double distance = geodesicDistance;
295 if ( dynamicGeodesicDistance )
298 distance = geodesicDistanceProperty.
valueAsDouble( expressionContext, distance );
301 std::unique_ptr< QgsMultiLineString > ml = std::make_unique< QgsMultiLineString >();
302 std::unique_ptr< QgsLineString > l = std::make_unique< QgsLineString >( QVector< QgsPoint >() << hubPoint );
304 QVector< QgsPointXY > points1 = points.at( 0 );
306 if ( points.count() == 1 )
310 l->append( &geodesicPoints );
311 if ( points.count() == 1 )
312 l->addVertex( spokePoint );
314 ml->addGeometry( l.release() );
315 if ( points.count() > 1 )
317 QVector< QgsPointXY > points2 = points.at( 1 );
319 l = std::make_unique< QgsLineString >( points2 );
321 l->addZValue( std::numeric_limits<double>::quiet_NaN() );
323 l->addMValue( std::numeric_limits<double>::quiet_NaN() );
325 l->addVertex( spokePoint );
326 ml->addGeometry( l.release() );
336 for (
int j = 0; j < spokeFeature.
attributes().count(); ++j )
338 if ( !spokeFieldIndices.contains( j ) )
340 spokeAttributes << spokeFeature.
attribute( j );
343 outAttributes.append( spokeAttributes );
352 outputs.insert( QStringLiteral(
"OUTPUT" ), dest );
WkbType
The WKB type describes the number of dimensions a geometry has.
@ MultiLineString
MultiLineString.
bool isMeasure() const
Returns true if the geometry contains m values.
bool is3D() const
Returns true if the geometry is 3D and contains a z-value.
A general purpose distance and area calculator, capable of performing ellipsoid based calculations.
QVector< QVector< QgsPointXY > > geodesicLine(const QgsPointXY &p1, const QgsPointXY &p2, double interval, bool breakLine=false) const
Calculates the geodesic line between p1 and p2, which represents the shortest path on the ellipsoid b...
void setSourceCrs(const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context)
Sets source spatial reference system crs.
QgsGeometry splitGeometryAtAntimeridian(const QgsGeometry &geometry) const
Splits a (Multi)LineString geometry at the antimeridian (longitude +/- 180 degrees).
bool setEllipsoid(const QString &ellipsoid)
Sets the ellipsoid by its acronym.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
void setFeature(const QgsFeature &feature)
Convenience function for setting a feature for the context.
static QString createFieldEqualityExpression(const QString &fieldName, const QVariant &value, QVariant::Type fieldType=QVariant::Type::Invalid)
Create an expression allowing to evaluate if a field is equal to a value.
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
This class wraps a request for features to a vector layer (or directly its vector data provider).
QgsFeatureRequest & setSubsetOfAttributes(const QgsAttributeList &attrs)
Set a subset of attributes that will be fetched.
QgsFeatureRequest & setDestinationCrs(const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context)
Sets the destination crs for feature's geometries.
QgsFeatureRequest & setFilterExpression(const QString &expression)
Set the filter expression.
@ FastInsert
Use faster inserts, at the cost of updating the passed features to reflect changes made at the provid...
@ RegeneratePrimaryKey
This flag indicates, that a primary key field cannot be guaranteed to be unique and the sink should i...
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
void setAttributes(const QgsAttributes &attrs)
Sets the feature's attributes.
bool hasGeometry() const
Returns true if the feature has an associated geometry.
QVariant attribute(const QString &name) const
Lookup attribute value by attribute name.
void setGeometry(const QgsGeometry &geometry)
Set the feature's geometry.
bool isCanceled() const
Tells whether the operation has been canceled already.
void setProgress(double progress)
Sets the current progress for the feedback object.
Container of fields for a vector layer.
bool append(const QgsField &field, FieldOrigin origin=OriginProvider, int originIndex=-1)
Appends a field. The field must have unique name, otherwise it is rejected (returns false)
int count() const
Returns number of items.
int lookupField(const QString &fieldName) const
Looks up field's index from the field name.
A geometry is the spatial representation of a feature.
Line string geometry type, with support for z-dimension and m-values.
A class to represent a 2D point.
Point geometry type, with support for z-dimension and m-values.
bool addMValue(double mValue=0) override
Adds a measure to the geometry, initialized to a preset value.
bool addZValue(double zValue=0) override
Adds a z-dimension to the geometry, initialized to a preset value.
Contains information about the context in which a processing algorithm is executed.
QgsCoordinateTransformContext transformContext() const
Returns the coordinate transform context.
QString ellipsoid() const
Returns the ellipsoid to use for distance and area calculations.
Custom exception class for processing related exceptions.
@ FlagSkipGeometryValidityChecks
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
Base class for providing feedback from a processing algorithm.
A boolean parameter for processing algorithms.
@ FlagAdvanced
Parameter is an advanced parameter which should be hidden from users by default.
A feature sink output for processing algorithms.
An input feature source (such as vector layers) parameter for processing algorithms.
A vector layer or feature source field parameter for processing algorithms.
static bool isDynamic(const QVariantMap ¶meters, const QString &name)
Returns true if the parameter with matching name is a dynamic parameter, and must be evaluated once f...
static QgsFields combineFields(const QgsFields &fieldsA, const QgsFields &fieldsB, const QString &fieldsBPrefix=QString())
Combines two field lists, avoiding duplicate field names (in a case-insensitive manner).
@ TypeVectorLine
Vector line layers.
Definition for a property.
@ DoublePositive
Positive double value (including 0)
A store for object properties.
QVariant value(const QgsExpressionContext &context, const QVariant &defaultValue=QVariant(), bool *ok=nullptr) const
Calculates the current value of the property, including any transforms which are set for the property...
double valueAsDouble(const QgsExpressionContext &context, double defaultValue=0.0, bool *ok=nullptr) const
Calculates the current value of the property and interprets it as a double.
static Qgis::WkbType addM(Qgis::WkbType type)
Adds the m dimension to a WKB type and returns the new type.
static Qgis::WkbType addZ(Qgis::WkbType type)
Adds the z dimension to a WKB type and returns the new type.
static bool hasZ(Qgis::WkbType type)
Tests whether a WKB type contains the z-dimension.
static bool hasM(Qgis::WkbType type)
Tests whether a WKB type contains m values.
QList< int > QgsAttributeList