mirror of
https://github.com/qgis/QGIS.git
synced 2025-02-25 00:58:06 -05:00
82 lines
3.1 KiB
Python
82 lines
3.1 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
RasterLayerHistogram.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.ParameterNumber import ParameterNumber
|
|
from processing.parameters.ParameterRaster import ParameterRaster
|
|
from processing.outputs.OutputTable import OutputTable
|
|
from processing.outputs.OutputHTML import OutputHTML
|
|
from processing.tools import dataobjects
|
|
from processing.tools import raster
|
|
|
|
|
|
class RasterLayerHistogram(GeoAlgorithm):
|
|
|
|
INPUT = 'INPUT'
|
|
PLOT = 'PLOT'
|
|
TABLE = 'TABLE'
|
|
BINS = 'BINS'
|
|
|
|
def processAlgorithm(self, progress):
|
|
uri = self.getParameterValue(self.INPUT)
|
|
layer = dataobjects.getObjectFromUri(uri)
|
|
outputplot = self.getOutputValue(self.PLOT)
|
|
outputtable = self.getOutputFromName(self.TABLE)
|
|
values = raster.scanraster(layer, progress)
|
|
nbins = self.getParameterValue(self.BINS)
|
|
|
|
# ALERT: this is potentially blocking if the layer is too big
|
|
plt.close()
|
|
valueslist = []
|
|
for v in values:
|
|
if v is not None:
|
|
valueslist.append(v)
|
|
(n, bins, values) = plt.hist(valueslist, nbins)
|
|
fields = [QgsField('CENTER_VALUE', QVariant.Double),
|
|
QgsField('NUM_ELEM', QVariant.Double)]
|
|
writer = outputtable.getTableWriter(fields)
|
|
for i in xrange(len(values)):
|
|
writer.addRecord([str(bins[i]) + '-' + str(bins[i + 1]), n[i]])
|
|
plotFilename = outputplot + '.png'
|
|
lab.savefig(plotFilename)
|
|
f = open(outputplot, 'w')
|
|
f.write('<img src="' + plotFilename + '"/>')
|
|
f.close()
|
|
|
|
def defineCharacteristics(self):
|
|
self.name = 'Raster layer histogram'
|
|
self.group = 'Graphics'
|
|
self.addParameter(ParameterRaster(self.INPUT, 'Input layer'))
|
|
self.addParameter(ParameterNumber(self.BINS, 'Number of bins', 2,
|
|
None, 10))
|
|
self.addOutput(OutputHTML(self.PLOT, 'Output plot'))
|
|
self.addOutput(OutputTable(self.TABLE, 'Output table'))
|