class Analyst(QObject):
  rangeChanged = pyqtSignal(int)
  updateProgress = pyqtSignal()
  processFinished = pyqtSignal(RasterMap)
def __init__(self, first, second):
  QObject.__init__(self)
  ...
def createMap(self):
  ...
  self.rangeChanged.emit(rows)
  for i in xrange(rows):
    # do something
    self.updateProgress.emit()
  data = RasterMap()
  data.create(...)
  self.processFinished.emit(data)

...
def createMap(self):
  analyst = Analyst(self.inputs["initial"], self.inputs["final"])
  analyst.processFinished.connect(self.mapCreated())
def changeMapDone(self, raster):
  # do something with raster