Write Your Own Geospatial Utilities - Open Source Geospatial Tools: Applications in Earth Observation - page 228

the number of sample points to generate, the bounding box and the output format.
We include a check for the bounding box to ensure that the lower extents are less
than the upper extents of the area of interest.

def main():
try:

parser = argparse.ArgumentParser()
parser.add_argument('-f','--frame_type',

→ help='Sampling frame design', required=True)

parser.add_argument('-s','--sample',

→ help='Number of samples', type=int, required=True)

parser.add_argument('-b','--bbox',

→

help='Bounding box', type=int, nargs=4, required=True)
parser.add_argument('-o','--output_format',

→

help='Output Format', default='Shp')

args = parser.parse_args()

frame_type = args.frame_type
n_sample = args.sample
bbox_list = args.bbox
output_format = args.output_format

#create a dictionary to hold the four coordinates of the

→ bounding box

bbox_dict = {'xmin': bbox_list[0],'ymin':

→

bbox_list[1],'xmax': bbox_list[2],'ymax': bbox_list[3]}

#check if xmin is greater than xmax and exit if it is
if bbox_dict['xmin'] > bbox_dict['xmax']:
print("Error xmin: "+

→

str(bbox_dict['xmin']) +" is greater than xmax: "+

→

str(bbox_dict['xmax']))
sys.exit(1)

#check if ymin is greater than ymax and exit if it is
if bbox_dict['ymin'] > bbox_dict['ymax']:
print("Error ymin: "+

→

str(bbox_dict['ymin']) +" is greater than ymax: "+

→

str(bbox_dict['ymax']))
sys.exit(1)

#call different function depending on type of sampling frame
if frame_type =="random":
print("Calling random frame...")
randomFrame(n_sample, bbox_dict,

→

output_format)
else:

print("Calling systematic frame...")
systematicFrame()

print'Created Sampling frame containing' +

→

str(n_sample) +' plots'

return 1

except:

sys.exit(1)
return 0