structure.py 文件源码

def areaxy(self, lowerbound=-np.inf, upperbound=np.inf, spacing=0.1):
        mask = (self.coord[:,2] > lowerbound) & (self.coord[:,2] < upperbound)
        points = self.coord[mask, :2]
        # The magic number factor 1.1 is not critical at all
        # Just a number to set a margin to the bounding box and 
        # have all points fall within the boundaries
        bbmin, bbmax = 1.1*points.min(axis=0), 1.1*points.max(axis=0)
        size = bbmax - bbmin
        cells = (size / spacing + 0.5).astype('int')
        # Grid points over bounding box with specified spacing
        grid = np.mgrid[bbmin[0]:bbmax[0]:(cells[0]*1j),
                        bbmin[1]:bbmax[1]:(cells[1]*1j)].reshape((2,-1)).T
        # Occupied cells is approximately equal to grid points within
        # gridspacing distance of points
        occupied = occupancy(grid, points, spacing)
        # The occupied area follows from the fraction of occupied
        # cells times the area spanned by the bounding box
        return size[0]*size[1]*sum(occupied > 0)/occupied.size