QGIS/python/plugins/processing/algs/qgis/VectorLayerScatterplot.py

73 lines
2.9 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 matplotlib.pyplot as plt
import matplotlib.pylab as lab
from PyQt4.QtCore import *
from qgis.core import *
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.parameters.ParameterVector import ParameterVector
from processing.parameters.ParameterTableField import ParameterTableField
from processing.parameters.ParameterNumber import ParameterNumber
from processing.outputs.OutputHTML import OutputHTML
from processing.tools import *
class VectorLayerScatterplot(GeoAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
XFIELD = 'XFIELD'
YFIELD = 'YFIELD'
def processAlgorithm(self, progress):
uri = self.getParameterValue(self.INPUT)
layer = getObjectFromUri(uri)
xfieldname = self.getParameterValue(self.YFIELD)
yfieldname = self.getParameterValue(self.XFIELD)
output = self.getOutputValue(self.OUTPUT)
values = vector.getAttributeValues(layer, xfieldname, yfieldname)
plt.close()
plt.scatter(values[xfieldname], values[yfieldname])
plotFilename = output + '.png'
lab.savefig(plotFilename)
f = open(output, 'w')
f.write('<img src="' + plotFilename + '"/>')
f.close()
def defineCharacteristics(self):
self.name = 'Vector layer scatterplot'
self.group = 'Graphics'
self.addParameter(ParameterVector(self.INPUT, 'Input layer',
[ParameterVector.VECTOR_TYPE_ANY]))
self.addParameter(ParameterTableField(self.XFIELD, 'X attribute',
self.INPUT, ParameterTableField.DATA_TYPE_NUMBER))
self.addParameter(ParameterTableField(self.YFIELD, 'Y attribute',
self.INPUT, ParameterTableField.DATA_TYPE_NUMBER))
self.addOutput(OutputHTML(self.OUTPUT, 'Output'))