QGIS/python/plugins/processing/algs/qgis/scripts/Frequency_analysis.py
2014-10-03 10:42:03 +02:00

36 lines
921 B
Python

##Table=group
##input=vector
##fields=string
##output=output table
from qgis.core import *
from PyQt4.QtCore import *
from processing.core.TableWriter import TableWriter
from collections import defaultdict
layer = processing.getObject(input)
inputFields = layer.pendingFields()
fieldIdxs = []
fields = fields.split(',')
for f in fields:
idx = inputFields.indexFromName(f)
if idx == -1:
raise GeoAlgorithmExecutionException('Field not found:' + f)
fieldIdxs.append(idx)
writer = TableWriter(output, None, fields + ['FREQ'])
counts = {}
feats = processing.features(layer)
nFeats = len(feats)
counts = defaultdict(int)
for i, feat in enumerate(feats):
progress.setPercentage(int(100 * i / nFeats))
attrs = feat.attributes()
clazz = tuple([attrs[idx] for idx in fieldIdxs])
print clazz
counts[clazz] += 1
for c in counts:
writer.addRecord(list(c) + [counts[c]])