def test_threshold_binaryW_from_array(self):
points = [(10, 10), (20, 10), (40, 10), (15, 20), (30, 20), (30, 30)]
w = pysal.threshold_binaryW_from_array(points, threshold=11.2)
self.assertEquals(w.weights, {0: [1, 1], 1: [1, 1], 2: [],
3: [1, 1], 4: [1], 5: [1]})
self.assertEquals(w.neighbors, {0: [1, 3], 1: [0, 3], 2: [
], 3: [1, 0], 4: [5], 5: [4]})
def calc_morans_i(self, raster_as_array, lag_distance=10):
"""
Calculates the value of Moran's I at given lag distances using Distance Band Weights;
Default ranges from 1 pixel to 10 pixels
In this particular project, that translates to: 1 pixel (30 m) to 10 pixels (300 m)
Reference: http://pysal.readthedocs.org/en/latest/users/tutorials/weights.html#distance-band-weights
@param raster_as_array: the raster to use in the calculations as an array
@param lag_distance: given lag distance
@returns: an array of Moran's I values.
"""
self.raster_as_array = raster_as_array
self.lag_distance = lag_distance
_flattened_raster_array = self.raster_as_array.ravel()
_x, _y = numpy.indices((self.rows, self.columns))
_x.shape = (self.rows * self.columns, 1)
_y.shape = (self.rows * self.columns, 1)
_horizontal_stack = numpy.hstack([_x, _y])
_Morans_I = numpy.zeros(self.lag_distance)
# Get weights based on distance (distance-band method) and calculation Moran's I
for i in range(1, self.lag_distance + 1):
_wthresh = pysal.threshold_binaryW_from_array(
_horizontal_stack, i) # distance-based weights
_mi = pysal.Moran(
_flattened_raster_array,
_wthresh) # calculate Moran's I for given distance
_Morans_I[
i -
1] = _mi.I # Value of individual result of Moran's I (_mi.I) saved into array
return _Morans_I
def buildWeights(self):
"""Performs Distance-based Weights Creation"""
ARCPY.SetProgressor("default", "Constructing spatial weights object...")
#### Shorthand Attributes ####
distanceType = self.distanceType
threshold = self.threshold
knnNum = self.knnNum
idField = self.idField
outputExt = self.outputExt
ssdo = self.ssdo
#### Create Distance-based WeightObj (0-based IDs) ####
dataArray = ssdo.xyCoords
if distanceType.upper() == DISTTYPE[0]:
weightObj = PYSAL.threshold_binaryW_from_array(dataArray, threshold)
elif distanceType.upper() == DISTTYPE[1]:
weightObj = PYSAL.knnW_from_array(dataArray, knnNum)
elif distanceType.upper() == DISTTYPE[2]:
alpha = -1 * self.inverseDist
weightObj = PYSAL.threshold_continuousW_from_array(\
dataArray, threshold, alpha=alpha)
#### Re-Create WeightObj for NOT 0-based idField ####
if idField:
if ssdo.master2Order.keys() != ssdo.master2Order.values():
o2M = ssdo.order2Master
neighborDict = {o2M[oid] : [o2M[nid] for nid in nbrs] \
for oid,nbrs in weightObj.neighbors.items()}
weightDict = {o2M[oid] : weights \
for oid, weights in weightObj.weights.items()}
weightObj = W(neighborDict, weightDict)
#### Save weightObj Class Object for Writing Result ####
self.weightObj = weightObj
def buildWeights(self):
"""Performs Distance-based Weights Creation"""
ARCPY.SetProgressor("default",
"Constructing spatial weights object...")
#### Shorthand Attributes ####
distanceType = self.distanceType
threshold = self.threshold
knnNum = self.knnNum
idField = self.idField
outputExt = self.outputExt
ssdo = self.ssdo
#### Create Distance-based WeightObj (0-based IDs) ####
dataArray = ssdo.xyCoords
if distanceType.upper() == DISTTYPE[0]:
weightObj = PYSAL.threshold_binaryW_from_array(
dataArray, threshold)
elif distanceType.upper() == DISTTYPE[1]:
weightObj = PYSAL.knnW_from_array(dataArray, knnNum)
elif distanceType.upper() == DISTTYPE[2]:
alpha = -1 * self.inverseDist
weightObj = PYSAL.threshold_continuousW_from_array(\
dataArray, threshold, alpha=alpha)
#### Re-Create WeightObj for NOT 0-based idField ####
if idField:
if ssdo.master2Order.keys() != ssdo.master2Order.values():
o2M = ssdo.order2Master
neighborDict = {o2M[oid] : [o2M[nid] for nid in nbrs] \
for oid,nbrs in weightObj.neighbors.items()}
weightDict = {o2M[oid] : weights \
for oid, weights in weightObj.weights.items()}
weightObj = W(neighborDict, weightDict)
#### Save weightObj Class Object for Writing Result ####
self.weightObj = weightObj
