def raster_average_mk2(rasterobject_list, outras):
# this function improves the previous version in that no value data is considered
from arcpy.sa import Con, SetNull, CellStatistics
n = len(rasterobject_list)
# get mask
rastermask_list = list()
for each in rasterobject_list:
eachmask = Con(each > 32760, 1, 0)
rastermask_list.append(eachmask)
sum_mask = CellStatistics(rastermask_list, "SUM")
# flip values and set null for mask
# only do this for pixels having more than 6 NoData
## sum_mask = Con(sum_mask>0, None, 1)
sum_mask = SetNull(sum_mask > 6, 1)
# it doesn't honor mask
outras_mask = r"C:\mask_temp.tif"
sum_mask.save(outras_mask)
# average, only operate on those valid values
arcpy.env.mask = outras_mask
# average
avg_raster = CellStatistics(rasterobject_list, "MEAN", "DATA")
avg_raster.save(outras)
# clear mask
arcpy.env.mask = None
def night_image_mean():
"""
从多年的night images生成一张均值image的栅格文件
"""
env.workspace = "G:\yang\ozone_process/night_images"
out_raster_name = "night_mean.tif"
if not os.path.exists(os.path.join(env.workspace, out_raster_name)):
night_images = get_night_images()
out_rasters = night_images_extract(night_images)
out_raster = CellStatistics(out_rasters, "MEAN", "DATA")
out_raster.save(out_raster_name)
return os.path.join(env.workspace, out_raster_name)
def evi_year_mean_stat():
years = YEARS
for year in years:
evi_raster_paths = glob.glob(
os.path.join(EVI_RASTER_SUBDIR,
"US{}*.250m_16_days_EVI.tif".format(str(year))))
output_raster_path = "evi_{}_mean_stat.tif".format(str(year))
if os.path.exists(os.path.join(env.workspace, output_raster_path)):
print("{} has been created before".format(output_raster_path))
continue
print("CellStatistics is working for {}".format(str(year)))
evi_year_stat = CellStatistics(evi_raster_paths, "MAXIMUM", "NODATA")
evi_year_stat.save(output_raster_path)