本文整理汇总了Python中qgis.core.QgsRasterFileWriter.createOneBandRaster方法的典型用法代码示例。如果您正苦于以下问题：Python QgsRasterFileWriter.createOneBandRaster方法的具体用法？Python QgsRasterFileWriter.createOneBandRaster怎么用？Python QgsRasterFileWriter.createOneBandRaster使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类qgis.core.QgsRasterFileWriter的用法示例。
在下文中一共展示了QgsRasterFileWriter.createOneBandRaster方法的2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: processAlgorithm
# 需要导入模块: from qgis.core import QgsRasterFileWriter [as 别名]
# 或者: from qgis.core.QgsRasterFileWriter import createOneBandRaster [as 别名]
def processAlgorithm(self, parameters, context, feedback):
crs = self.parameterAsCrs(parameters, self.TARGET_CRS, context)
extent = self.parameterAsExtent(parameters, self.EXTENT, context, crs)
value = self.parameterAsDouble(parameters, self.NUMBER, context)
pixelSize = self.parameterAsDouble(parameters, self.PIXEL_SIZE, context)
outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
outputFormat = QgsRasterFileWriter.driverForExtension(os.path.splitext(outputFile)[1])
rows = max([math.ceil(extent.height() / pixelSize) + 1, 1.0])
cols = max([math.ceil(extent.width() / pixelSize) + 1, 1.0])
writer = QgsRasterFileWriter(outputFile)
writer.setOutputProviderKey('gdal')
writer.setOutputFormat(outputFormat)
provider = writer.createOneBandRaster(Qgis.Float32, cols, rows, extent, crs)
provider.setNoDataValue(1, -9999)
data = [value] * cols
block = QgsRasterBlock(Qgis.Float32, cols, 1)
block.setData(struct.pack('{}f'.format(len(data)), *data))
total = 100.0 / rows if rows else 0
for i in range(rows):
if feedback.isCanceled():
break
provider.writeBlock(block, 1, 0, i)
feedback.setProgress(int(i * rows))
provider.setEditable(False)
return {self.OUTPUT: outputFile}示例2: processAlgorithm
# 需要导入模块: from qgis.core import QgsRasterFileWriter [as 别名]
# 或者: from qgis.core.QgsRasterFileWriter import createOneBandRaster [as 别名]
def processAlgorithm(self, parameters, context, feedback):
layer = self.parameterAsMeshLayer(parameters, self.INPUT_LAYER, context)
dataset = parameters[self.INPUT_DATASET_GROUP]
timestep = parameters[self.INPUT_TIMESTEP]
mupp = self.parameterAsDouble(
parameters,
self.MAP_UNITS_PER_PIXEL,
context)
extent = self.parameterAsExtent(
parameters,
self.INPUT_EXTENT,
context)
output_layer = self.parameterAsOutputLayer(
parameters,
self.OUTPUT,
context)
if dataset is None:
raise QgsProcessingException(u'No dataset group selected')
width = extent.width()/mupp
height = extent.height()/mupp
map_settings = qgis.utils.iface.mapCanvas().mapSettings()
crs = map_settings.destinationCrs()
transform_context = QgsProject.instance().transformContext()
output_format = QgsRasterFileWriter.driverForExtension(os.path.splitext(output_layer)[1])
rfw = QgsRasterFileWriter(output_layer)
rfw.setOutputProviderKey('gdal')
rfw.setOutputFormat(output_format)
rdp = rfw.createOneBandRaster(
Qgis.Float64,
width,
height,
extent,
crs
)
if rdp is None:
raise QgsProcessingException(self.tr("Could not create raster output: {}").format(output_layer))
if not rdp.isValid():
raise QgsProcessingException(
self.tr("Could not create raster output {}: {}").format(
output_layer,
rdp.error().message(QgsErrorMessage.Text)
)
)
rdp.setEditable(True)
nr_timesteps = layer.dataProvider().datasetCount(QgsMeshDatasetIndex(dataset))
if nr_timesteps == 1:
timestep = 0
dataset_index = QgsMeshDatasetIndex(dataset, timestep)
block = QgsMeshUtils.exportRasterBlock(
layer,
dataset_index,
crs,
transform_context,
mupp,
extent
)
rdp.writeBlock(block, 1)
rdp.setNoDataValue(1, block.noDataValue())
rdp.setEditable(False)
feedback.setProgress(100)
return {self.OUTPUT: output_layer}