DM_numpy_spatial_query2.py

## @package python.demo.DM_numpy_spatial_query2
# "
# example script showing how to load an OPALS datamanager,
# perform a spatial query and changing attribute values using
# numpy arrays
# 
 
from __future__ import print_function  # print function syntax as in python 3
import sys
 
from opals import pyDM
 
def DM_spatial_query_and_classify(filename, classValue):
  # open datamanager with write access
  dm = pyDM.Datamanager.load(filename, readOnly=False, threadSafety=False)
  if not dm:
    print("Unable to open ODM '" + filename + "'")
    sys.exit(1)
 
  # output some pyDM statistic
  limit = dm.getLimit()
  print("ODM contains", dm.sizePoint(), "points")
  print("2D-limit (%.3f," % limit.xmin, "%.3f) -" % limit.ymin, "(%.3f," % limit.xmax, "%.3f)" % limit.ymax)
 
  # build layout for attributes of interest (subset of odm attributes)
  lf = pyDM.AddInfoLayoutFactory()
  type, inDM = lf.addColumn(dm, "Id", True);             assert inDM == True
  type, inDM = lf.addColumn(dm, "Classification", True); assert inDM == True
  layout = lf.getLayout()
 
  # Create query object
  queryWin = pyDM.Window(529600, 5338600, 529650, 5338650) # window
  print("\nPerform spatial query")
  result = pyDM.NumpyConverter.searchPoint(dm, queryWin, layout, withCoordinates=True) # window query
 
  # number of points found
  ptsQueried = result[next(iter(result))].size
  print(f"{ptsQueried} points queried")
 
  if ptsQueried == 0:
    return
 
  print(f"Change selected points to classification {classValue}")
  classArray = result["Classification"]
  classArray.fill(classValue)
 
  # Create a new dict only containing the relevant numpy arrays
  setObj = {}
  setObj["Id"] = result["Id"]       # we need the ids to identify the points
  setObj["Classification"] = classArray # those are the changed classification values
 
  # write changed attribute values to the ODM
  pyDM.NumpyConverter.setById(setObj, dm, layout)
 
  print(f"Save ODM")
  dm.save()
 
 
if len(sys.argv) == 1:
    print("ODM parameter missing")
    sys.exit(-1)
 
DM_spatial_query_and_classify(sys.argv[1], classValue=6)