本文整理汇总了Python中qgis.core.QgsLineString类的典型用法代码示例。如果您正苦于以下问题：Python QgsLineString类的具体用法？Python QgsLineString怎么用？Python QgsLineString使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了QgsLineString类的4个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: convertToPolygon
def convertToPolygon(self, geom):
if QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.PointGeometry and geom.constGet().nCoordinates() < 3:
raise QgsProcessingException(
self.tr('Cannot convert from Point to Polygon').format(QgsWkbTypes.displayString(geom.wkbType())))
elif QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.PointGeometry:
# multipoint with at least 3 points
# TODO: mega inefficient - needs rework when geometry iterators land
# (but at least it doesn't lose Z/M values)
points = []
for g in geom.constGet().coordinateSequence():
for r in g:
for p in r:
points.append(p)
linestring = QgsLineString(points)
linestring.close()
p = QgsPolygon()
p.setExteriorRing(linestring)
return [QgsGeometry(p)]
elif QgsWkbTypes.geometryType(geom.wkbType()) == QgsWkbTypes.LineGeometry:
if QgsWkbTypes.isMultiType(geom):
parts = []
for i in range(geom.constGet().numGeometries()):
p = QgsPolygon()
linestring = geom.constGet().geometryN(i).clone()
linestring.close()
p.setExteriorRing(linestring)
parts.append(QgsGeometry(p))
return QgsGeometry.collectGeometry(parts)
else:
# linestring to polygon
p = QgsPolygon()
linestring = geom.constGet().clone()
linestring.close()
p.setExteriorRing(linestring)
return [QgsGeometry(p)]
else:
#polygon
if QgsWkbTypes.isMultiType(geom):
return geom.asGeometryCollection()
else:
return [geom]示例2: processAlgorithm
def processAlgorithm(self, parameters, context, feedback):
hSpacing = self.parameterAsDouble(parameters, self.HSPACING, context)
vSpacing = self.parameterAsDouble(parameters, self.VSPACING, context)
hOverlay = self.parameterAsDouble(parameters, self.HOVERLAY, context)
vOverlay = self.parameterAsDouble(parameters, self.VOVERLAY, context)
crs = self.parameterAsCrs(parameters, self.CRS, context)
bbox = self.parameterAsExtent(parameters, self.EXTENT, context, crs)
width = bbox.width()
height = bbox.height()
if hSpacing <= 0 or vSpacing <= 0:
raise QgsProcessingException(
self.tr('Invalid grid spacing: {0}/{1}').format(hSpacing, vSpacing))
if hSpacing <= hOverlay or vSpacing <= vOverlay:
raise QgsProcessingException(
self.tr('Invalid overlay: {0}/{1}').format(hOverlay, vOverlay))
if width < hSpacing:
raise QgsProcessingException(
self.tr('Horizontal spacing is too small for the covered area'))
if height < vSpacing:
raise QgsProcessingException(
self.tr('Vertical spacing is too small for the covered area'))
fields = QgsFields()
fields.append(QgsField('left', QVariant.Double, '', 24, 16))
fields.append(QgsField('top', QVariant.Double, '', 24, 16))
fields.append(QgsField('right', QVariant.Double, '', 24, 16))
fields.append(QgsField('bottom', QVariant.Double, '', 24, 16))
fields.append(QgsField('id', QVariant.Int, '', 10, 0))
fields.append(QgsField('coord', QVariant.Double, '', 24, 15))
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, QgsWkbTypes.LineString, crs)
if hOverlay > 0:
hSpace = [hSpacing - hOverlay, hOverlay]
else:
hSpace = [hSpacing, hSpacing]
if vOverlay > 0:
vSpace = [vSpacing - vOverlay, vOverlay]
else:
vSpace = [vSpacing, vSpacing]
feat = QgsFeature()
feat.initAttributes(len(fields))
count = 0
id = 1
# latitude lines
count_max = height / vSpacing
count_update = count_max * 0.10
y = bbox.yMaximum()
while y >= bbox.yMinimum():
if feedback.isCanceled():
break
pt1 = QgsPoint(bbox.xMinimum(), y)
pt2 = QgsPoint(bbox.xMaximum(), y)
line = QgsLineString()
line.setPoints([pt1, pt2])
feat.setGeometry(QgsGeometry(line))
feat.setAttributes([bbox.xMinimum(),
y,
bbox.xMaximum(),
y,
id,
y])
sink.addFeature(feat, QgsFeatureSink.FastInsert)
y = y - vSpace[count % 2]
id += 1
count += 1
if int(math.fmod(count, count_update)) == 0:
feedback.setProgress(int(count / count_max * 50))
feedback.setProgress(50)
# longitude lines
# counters for progressbar - update every 5%
count = 0
count_max = width / hSpacing
count_update = count_max * 0.10
x = bbox.xMinimum()
while x <= bbox.xMaximum():
if feedback.isCanceled():
break
pt1 = QgsPoint(x, bbox.yMaximum())
pt2 = QgsPoint(x, bbox.yMinimum())
line = QgsLineString()
line.setPoints([pt1, pt2])
feat.setGeometry(QgsGeometry(line))
feat.setAttributes([x,
bbox.yMaximum(),
#.........这里部分代码省略.........
示例3: testQgsLineStringRepr
def testQgsLineStringRepr(self):
ls = QgsLineString([QgsPoint(10, 2), QgsPoint(10, 1), QgsPoint(5, 1)])
self.assertEqual(ls.__repr__(), '<QgsLineString: LineString (10 2, 10 1, 5 1)>')示例4: processAlgorithm
def processAlgorithm(self, parameters, context, feedback):
extent = self.getParameterValue(self.EXTENT).split(',')
hSpacing = self.getParameterValue(self.HSPACING)
vSpacing = self.getParameterValue(self.VSPACING)
hOverlay = self.getParameterValue(self.HOVERLAY)
vOverlay = self.getParameterValue(self.VOVERLAY)
crs = QgsCoordinateReferenceSystem(self.getParameterValue(self.CRS))
bbox = QgsRectangle(float(extent[0]), float(extent[2]),
float(extent[1]), float(extent[3]))
width = bbox.width()
height = bbox.height()
if hSpacing <= 0 or vSpacing <= 0:
raise GeoAlgorithmExecutionException(
self.tr('Invalid grid spacing: {0}/{1}').format(hSpacing, vSpacing))
if hSpacing <= hOverlay or vSpacing <= vOverlay:
raise GeoAlgorithmExecutionException(
self.tr('Invalid overlay: {0}/{1}').format(hOverlay, vOverlay))
if width < hSpacing:
raise GeoAlgorithmExecutionException(
self.tr('Horizontal spacing is too small for the covered area'))
if height < vSpacing:
raise GeoAlgorithmExecutionException(
self.tr('Vertical spacing is too small for the covered area'))
fields = QgsFields()
fields.append(QgsField('left', QVariant.Double, '', 24, 16))
fields.append(QgsField('top', QVariant.Double, '', 24, 16))
fields.append(QgsField('right', QVariant.Double, '', 24, 16))
fields.append(QgsField('bottom', QVariant.Double, '', 24, 16))
fields.append(QgsField('id', QVariant.Int, '', 10, 0))
fields.append(QgsField('coord', QVariant.Double, '', 24, 15))
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields, QgsWkbTypes.LineString, crs, context)
if hOverlay > 0:
hSpace = [hSpacing - hOverlay, hOverlay]
else:
hSpace = [hSpacing, hSpacing]
if vOverlay > 0:
vSpace = [vSpacing - vOverlay, vOverlay]
else:
vSpace = [vSpacing, vSpacing]
feat = QgsFeature()
feat.initAttributes(len(fields))
count = 0
id = 1
# latitude lines
count_max = height / vSpacing
count_update = count_max * 0.10
y = bbox.yMaximum()
while y >= bbox.yMinimum():
pt1 = QgsPoint(bbox.xMinimum(), y)
pt2 = QgsPoint(bbox.xMaximum(), y)
line = QgsLineString()
line.setPoints([pt1, pt2])
feat.setGeometry(QgsGeometry(line))
feat.setAttributes([bbox.xMinimum(),
y,
bbox.xMaximum(),
y,
id,
y])
writer.addFeature(feat, QgsFeatureSink.FastInsert)
y = y - vSpace[count % 2]
id += 1
count += 1
if int(math.fmod(count, count_update)) == 0:
feedback.setProgress(int(count / count_max * 50))
feedback.setProgress(50)
# longitude lines
# counters for progressbar - update every 5%
count = 0
count_max = width / hSpacing
count_update = count_max * 0.10
x = bbox.xMinimum()
while x <= bbox.xMaximum():
pt1 = QgsPoint(x, bbox.yMaximum())
pt2 = QgsPoint(x, bbox.yMinimum())
line = QgsLineString()
line.setPoints([pt1, pt2])
feat.setGeometry(QgsGeometry(line))
feat.setAttributes([x,
bbox.yMaximum(),
x,
bbox.yMinimum(),
id,
x])
writer.addFeature(feat, QgsFeatureSink.FastInsert)
#.........这里部分代码省略.........