def get_north_shifted_point(dem,offset=0.001):
newPoint = Point(lon=dem.center.lon, lat=dem.center.lat+offset)
newPoint.lonlat_to_pixel(dem.geotransform, dem.projection)
return newPoint
aspects = ImgData(os.path.join(folder,'big_spider_aspects.tif')) # spider1 = ImgData(os.path.join(folder,'ESP_022607_0985_cropped_big_spider.cub')) # spider2 = ImgData(os.path.join(folder,'ESP_022699_0985_cropped_big_spider.cub')) # read in required data dem.read_all() slopes.read_all() aspects.read_all() # plt.imshow(dem.data,aspect='auto') # plt.plot(dem.center.sample,dem.center.line, 'r*',markersize=10) # determine angle between north and top to correct aspect angles that count like # north is at the top of the image newPoint = Point(lon=dem.center.lon, lat=dem.center.lat+0.001) newPoint.lonlat_to_pixel(dem.geotransform, dem.projection) # plt.plot(newPoint.sample, newPoint.line, 'g*', markersize=10) v1 = np.array((newPoint.x - dem.center.x, newPoint.y - dem.center.y)) # delta between north and top of image delta_angle = np.degrees(np.arctan2(v1[1],v1[0]))-90.0 # dsample = newPoint.sample - dem.center.sample # dline = newPoint.line - dem.center.line # plt.quiver(dem.center.sample,dem.center.line,dsample,dline,angles='xy', scale_units='xy', scale=1) # correct aspects for delta angle # it needs to be added, because aspects go clock-wise aspects.data += delta_angle # bend around data > 360 mask = aspects.data > 360.0 aspects.data[mask] = aspects.data[mask] - 360.0