Add a small random number to DEM when calculating flow direction, to smooth flat areas

This commit is contained in:
Gael-de-Sailly 2020-04-11 14:27:56 +02:00
parent 8b78f6c5b4
commit ecba126983

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@ -18,11 +18,13 @@ neighbours_dirs = np.array([
neighbours_pattern = neighbours_dirs > 0
def flow_dirs_lakes(dem):
def flow_dirs_lakes(dem, random=0.0625):
(Y, X) = dem.shape
dem_margin = np.zeros((Y+2, X+2))
dem_margin[1:-1,1:-1] = dem
if random > 0:
dem_margin += np.random.random(dem_margin.shape) * random
# Initialize: list map borders
borders = []
@ -72,7 +74,7 @@ def accumulate(dirs, dem=None):
(Y, X) = dirs.shape
dirs_margin = np.zeros((Y+2,X+2))-1
dirs_margin[1:-1,1:-1] = dirs
quantity = np.zeros((Y, X), dtype='u4')
quantity = np.zeros((Y, X), dtype='i4')
def calculate_quantity(y, x):
if quantity[y,x] > 0: