QGIS/python/plugins/processing/algs/qgis/VectorLayerHistogram.py
2017-08-30 07:28:25 +10:00

85 lines
3.3 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
EquivalentNumField.py
---------------------
Date : January 2013
Copyright : (C) 2013 by Victor Olaya
Email : volayaf at gmail dot com
***************************************************************************
* *
* 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. *
* *
***************************************************************************
"""
__author__ = 'Victor Olaya'
__date__ = 'January 2013'
__copyright__ = '(C) 2013, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import plotly as plt
import plotly.graph_objs as go
from qgis.core import (QgsProcessingParameterFeatureSource,
QgsProcessingParameterField,
QgsProcessingParameterNumber,
QgsProcessingParameterFileDestination,
QgsProcessingOutputHtml)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
from processing.tools import vector
class VectorLayerHistogram(QgisAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
FIELD = 'FIELD'
BINS = 'BINS'
def group(self):
return self.tr('Graphics')
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
self.tr('Input layer')))
self.addParameter(QgsProcessingParameterField(self.FIELD,
self.tr('Attribute'), parentLayerParameterName=self.INPUT,
type=QgsProcessingParameterField.Numeric))
self.addParameter(QgsProcessingParameterNumber(self.BINS,
self.tr('number of bins'), minValue=2, defaultValue=10))
self.addParameter(QgsProcessingParameterFileDestination(self.OUTPUT, self.tr('Histogram'), self.tr('HTML files (*.html)')))
self.addOutput(QgsProcessingOutputHtml(self.OUTPUT, self.tr('Histogram')))
def name(self):
return 'vectorlayerhistogram'
def displayName(self):
return self.tr('Vector layer histogram')
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
fieldname = self.parameterAsString(parameters, self.FIELD, context)
bins = self.parameterAsInt(parameters, self.BINS, context)
output = self.parameterAsFileOutput(parameters, self.OUTPUT, context)
values = vector.values(source, fieldname)
data = [go.Histogram(x=values[fieldname],
nbinsx=bins)]
plt.offline.plot(data, filename=output, auto_open=False)
return {self.OUTPUT: output}