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96 lines
3.9 KiB
Python
96 lines
3.9 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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VectorLayerHistogram.py
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---------------------
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Date : January 2013
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Copyright : (C) 2013 by Victor Olaya
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Email : volayaf at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Victor Olaya'
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__date__ = 'January 2013'
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__copyright__ = '(C) 2013, Victor Olaya'
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import warnings
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from qgis.core import (QgsProcessingException,
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QgsProcessingParameterFeatureSource,
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QgsProcessingParameterField,
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QgsProcessingParameterNumber,
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QgsProcessingParameterFileDestination)
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from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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from processing.tools import vector
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from qgis.PyQt.QtCore import QCoreApplication
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class VectorLayerHistogram(QgisAlgorithm):
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INPUT = 'INPUT'
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OUTPUT = 'OUTPUT'
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FIELD = 'FIELD'
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BINS = 'BINS'
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def group(self):
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return self.tr('Plots')
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def groupId(self):
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return 'plots'
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def __init__(self):
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super().__init__()
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def initAlgorithm(self, config=None):
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self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
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self.tr('Input layer')))
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self.addParameter(QgsProcessingParameterField(self.FIELD,
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self.tr('Attribute'), parentLayerParameterName=self.INPUT,
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type=QgsProcessingParameterField.Numeric))
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self.addParameter(QgsProcessingParameterNumber(self.BINS,
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self.tr('number of bins'), minValue=2, defaultValue=10))
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self.addParameter(QgsProcessingParameterFileDestination(self.OUTPUT, self.tr('Histogram'), self.tr('HTML files (*.html)')))
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def name(self):
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return 'vectorlayerhistogram'
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def displayName(self):
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return self.tr('Vector layer histogram')
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def processAlgorithm(self, parameters, context, feedback):
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try:
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# importing plotly throws Python warnings from within the library - filter these out
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with warnings.catch_warnings():
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warnings.filterwarnings("ignore", category=ResourceWarning)
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warnings.filterwarnings("ignore", category=ImportWarning)
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import plotly as plt
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import plotly.graph_objs as go
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except ImportError:
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raise QgsProcessingException(QCoreApplication.translate('VectorLayerHistogram', 'This algorithm requires the Python “plotly” library. Please install this library and try again.'))
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source = self.parameterAsSource(parameters, self.INPUT, context)
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if source is None:
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raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
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fieldname = self.parameterAsString(parameters, self.FIELD, context)
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bins = self.parameterAsInt(parameters, self.BINS, context)
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output = self.parameterAsFileOutput(parameters, self.OUTPUT, context)
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values = vector.values(source, fieldname)
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data = [go.Histogram(x=values[fieldname],
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nbinsx=bins)]
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plt.offline.plot(data, filename=output, auto_open=False)
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return {self.OUTPUT: output}
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