mirror of
https://github.com/qgis/QGIS.git
synced 2025-03-08 00:02:35 -05:00
91eea30e7d
If you have a layer with an unknown CRS, this algorithm gives a list of possible candidate CRSes which the layer could be in. It allows users to set the area (and corresponding CRS) which they know the layer should be located near. The algorithm then tests every CRS in the database to see what candidate CRSes would cause the layer to be located at that preset area. It's much faster than it sounds!! (just a couple of seconds) Sponsored by SMEC/Surbana Jurong
117 lines
4.6 KiB
Python
117 lines
4.6 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
FindProjection.py
|
|
-----------------
|
|
Date : February 2017
|
|
Copyright : (C) 2017 by Nyall Dawson
|
|
Email : nyall dot dawson 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__ = 'Nyall Dawson'
|
|
__date__ = 'February 2017'
|
|
__copyright__ = '(C) 2017, Nyall Dawson'
|
|
|
|
# This will get replaced with a git SHA1 when you do a git archive
|
|
|
|
__revision__ = '$Format:%H$'
|
|
|
|
import os
|
|
import codecs
|
|
|
|
from qgis.core import (QgsGeometry,
|
|
QgsRectangle,
|
|
QgsCoordinateReferenceSystem,
|
|
QgsCoordinateTransform)
|
|
|
|
from processing.core.GeoAlgorithm import GeoAlgorithm
|
|
from processing.core.parameters import ParameterVector
|
|
from processing.core.parameters import ParameterCrs
|
|
from processing.core.parameters import ParameterExtent
|
|
from processing.core.outputs import OutputHTML
|
|
from processing.tools import dataobjects
|
|
|
|
|
|
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
|
|
|
|
|
|
class FindProjection(GeoAlgorithm):
|
|
|
|
INPUT_LAYER = 'INPUT_LAYER'
|
|
TARGET_AREA = 'TARGET_AREA'
|
|
TARGET_AREA_CRS = 'TARGET_AREA_CRS'
|
|
OUTPUT_HTML_FILE = 'OUTPUT_HTML_FILE'
|
|
|
|
def defineCharacteristics(self):
|
|
self.name, self.i18n_name = self.trAlgorithm('Find projection')
|
|
self.group, self.i18n_group = self.trAlgorithm('Vector general tools')
|
|
self.tags = self.tr('crs,srs,coordinate,reference,system,guess,estimate,finder,determine')
|
|
|
|
self.addParameter(ParameterVector(self.INPUT_LAYER,
|
|
self.tr('Input layer')))
|
|
extent_parameter = ParameterExtent(self.TARGET_AREA,
|
|
self.tr('Target area for layer'),
|
|
self.INPUT_LAYER)
|
|
extent_parameter.skip_crs_check = True
|
|
self.addParameter(extent_parameter)
|
|
self.addParameter(ParameterCrs(self.TARGET_AREA_CRS, 'Target area CRS'))
|
|
|
|
self.addOutput(OutputHTML(self.OUTPUT_HTML_FILE,
|
|
self.tr('Candidates')))
|
|
|
|
def processAlgorithm(self, feedback):
|
|
layer = dataobjects.getObjectFromUri(
|
|
self.getParameterValue(self.INPUT_LAYER))
|
|
|
|
extent = self.getParameterValue(self.TARGET_AREA).split(',')
|
|
target_crs = QgsCoordinateReferenceSystem(self.getParameterValue(self.TARGET_AREA_CRS))
|
|
|
|
target_geom = QgsGeometry.fromRect(QgsRectangle(float(extent[0]), float(extent[2]),
|
|
float(extent[1]), float(extent[3])))
|
|
|
|
output_file = self.getOutputValue(self.OUTPUT_HTML_FILE)
|
|
|
|
# make intersection tests nice and fast
|
|
engine = QgsGeometry.createGeometryEngine(target_geom.geometry())
|
|
engine.prepareGeometry()
|
|
|
|
layer_bounds = QgsGeometry.fromRect(layer.extent())
|
|
|
|
results = []
|
|
|
|
for srs_id in QgsCoordinateReferenceSystem.validSrsIds():
|
|
candidate_crs = QgsCoordinateReferenceSystem.fromSrsId(srs_id)
|
|
if not candidate_crs.isValid():
|
|
continue
|
|
|
|
transform_candidate = QgsCoordinateTransform(candidate_crs, target_crs)
|
|
transformed_bounds = QgsGeometry(layer_bounds)
|
|
try:
|
|
if not transformed_bounds.transform(transform_candidate) == 0:
|
|
continue
|
|
except:
|
|
continue
|
|
|
|
if engine.intersects(transformed_bounds.geometry()):
|
|
results.append(candidate_crs.authid())
|
|
|
|
self.createHTML(output_file, results)
|
|
|
|
def createHTML(self, outputFile, candidates):
|
|
with codecs.open(outputFile, 'w', encoding='utf-8') as f:
|
|
f.write('<html><head>\n')
|
|
f.write('<meta http-equiv="Content-Type" content="text/html; \
|
|
charset=utf-8" /></head><body>\n')
|
|
for c in candidates:
|
|
f.write('<p>' + c + '</p>\n')
|
|
f.write('</body></html>\n')
|