2020-05-18 13:55:44 +08:00

99 lines
4.1 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
BarPlot.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'
import warnings
from qgis.core import (QgsFeatureRequest,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterField,
QgsProcessingException,
QgsProcessingParameterFileDestination)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
from processing.tools import vector
from qgis.PyQt.QtCore import QCoreApplication
class BarPlot(QgisAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
NAME_FIELD = 'NAME_FIELD'
VALUE_FIELD = 'VALUE_FIELD'
def group(self):
return self.tr('Plots')
def groupId(self):
return 'plots'
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
self.tr('Input layer')))
self.addParameter(QgsProcessingParameterField(self.NAME_FIELD,
self.tr('Category name field'),
None, self.INPUT, QgsProcessingParameterField.Any))
self.addParameter(QgsProcessingParameterField(self.VALUE_FIELD,
self.tr('Value field'),
None, self.INPUT, QgsProcessingParameterField.Numeric))
self.addParameter(QgsProcessingParameterFileDestination(self.OUTPUT, self.tr('Bar plot'), self.tr('HTML files (*.html)')))
def name(self):
return 'barplot'
def displayName(self):
return self.tr('Bar plot')
def processAlgorithm(self, parameters, context, feedback):
try:
# importing plotly throws Python warnings from within the library - filter these out
with warnings.catch_warnings():
warnings.filterwarnings("ignore", category=ResourceWarning)
warnings.filterwarnings("ignore", category=ImportWarning)
import plotly as plt
import plotly.graph_objs as go
except ImportError:
raise QgsProcessingException(QCoreApplication.translate('BarPlot', 'This algorithm requires the Python “plotly” library. Please install this library and try again.'))
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
namefieldname = self.parameterAsString(parameters, self.NAME_FIELD, context)
valuefieldname = self.parameterAsString(parameters, self.VALUE_FIELD, context)
output = self.parameterAsFileOutput(parameters, self.OUTPUT, context)
values = vector.values(source, valuefieldname)
x_var = vector.convert_nulls([i[namefieldname] for i in source.getFeatures(QgsFeatureRequest().setFlags(QgsFeatureRequest.NoGeometry))], '<NULL>')
data = [go.Bar(x=x_var,
y=values[valuefieldname])]
plt.offline.plot(data, filename=output, auto_open=False)
return {self.OUTPUT: output}