2025-06-05 11:48:44 +10:00

176 lines
5.6 KiB
Python

"""
***************************************************************************
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,
QgsProcessingParameterString,
)
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"
TITLE = "TITLE"
XAXIS_TITLE = "XAXIS_TITLE"
YAXIS_TITLE = "YAXIS_TITLE"
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.DataType.Any,
)
)
self.addParameter(
QgsProcessingParameterField(
self.VALUE_FIELD,
self.tr("Value field"),
None,
self.INPUT,
QgsProcessingParameterField.DataType.Numeric,
)
)
self.addParameter(
QgsProcessingParameterFileDestination(
self.OUTPUT, self.tr("Bar plot"), self.tr("HTML files (*.html)")
)
)
self.addParameter(
QgsProcessingParameterString(self.TITLE, self.tr("Title"), optional=True)
)
self.addParameter(
QgsProcessingParameterString(
self.XAXIS_TITLE, self.tr("X-axis title"), optional=True
)
)
self.addParameter(
QgsProcessingParameterString(
self.YAXIS_TITLE, self.tr("Y-axis title"), optional=True
)
)
def name(self):
return "barplot"
def displayName(self):
return self.tr("Bar plot")
def shortDescription(self):
return self.tr("Creates a bar plot from a category and a layer field.")
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)
title = self.parameterAsString(parameters, self.TITLE, context)
xaxis_title = self.parameterAsString(parameters, self.XAXIS_TITLE, context)
yaxis_title = self.parameterAsString(parameters, self.YAXIS_TITLE, context)
if title.strip() == "":
title = None
if xaxis_title == "":
xaxis_title = namefieldname
elif xaxis_title == " ":
xaxis_title = None
if yaxis_title == "":
yaxis_title = valuefieldname
elif yaxis_title == " ":
yaxis_title = None
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.Flag.NoGeometry)
)
],
"<NULL>",
)
data = [go.Bar(x=x_var, y=values[valuefieldname])]
fig = go.Figure(
data=data,
layout_title_text=title,
layout_xaxis_title=xaxis_title,
layout_yaxis_title=yaxis_title,
)
fig.write_html(output)
return {self.OUTPUT: output}