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section 5.5 public
xarraytopo
Commits
59fc8e08
Commit
59fc8e08
authored
Nov 08, 2018
by
gcordonnier
Browse files
add d4/d8 option
parent
19c8a630
Changes
1
Hide whitespace changes
Inline
Sidebyside
xtopo/algos/flow_routing.py
View file @
59fc8e08
...
...
@@ 14,14 +14,23 @@ def reset_receivers(receivers, nnodes):
@
numba
.
njit
def
compute_receivers
_d8
(
receivers
,
dist2receivers
,
elevation
,
def
compute_receivers
(
receivers
,
dist2receivers
,
elevation
,
active_nodes
,
nx
,
ny
,
dx
,
dy
):
# queen (D8) neighbor lookup
dr
=
np
.
array
([

1
,

1
,

1
,
0
,
0
,
1
,
1
,
1
],
dtype
=
np
.
intp
)
dc
=
np
.
array
([

1
,
0
,
1
,

1
,
1
,

1
,
0
,
1
],
dtype
=
np
.
intp
)
nx
,
ny
,
dx
,
dy
,
directions
=
8
):
if
directions
==
8
:
# queen (D8) neighbor lookup
dr
=
(

1
,

1
,

1
,
0
,
0
,
1
,
1
,
1
)
dc
=
(

1
,
0
,
1
,

1
,
1
,

1
,
0
,
1
)
else
:
directions
=
4
# king (D4) neighbor lookup
dr
=
(

1
,
0
,
0
,
1
,
0
,
0
,
0
,
0
)
dc
=
(
0
,

1
,
1
,
0
,
0
,
0
,
0
,
0
)
length
=
[
math
.
sqrt
((
dy
*
dr
[
i
])
**
2
+
(
dx
*
dc
[
i
])
**
2
)
for
i
in
range
(
8
)]
length
=
np
.
sqrt
((
dy
*
dr
)
**
2
+
(
dx
*
dc
)
**
2
)
tiny
=
np
.
finfo
(
elevation
.
dtype
).
tiny
...
...
@@ 34,7 +43,7 @@ def compute_receivers_d8(receivers, dist2receivers, elevation,
slope_max
=
tiny
for
k
in
range
(
8
):
for
k
in
range
(
directions
):
if
r
+
dr
[
k
]
>=
0
and
r
+
dr
[
k
]
<
ny
and
c
+
dc
[
k
]
>=
0
and
c
+
dc
[
k
]
<
nx
:
ineighbor
=
(
r
+
dr
[
k
])
*
nx
+
(
c
+
dc
[
k
])
slope
=
(
elevation
[
inode
]

elevation
[
ineighbor
])
/
length
[
k
]
...
...
@@ 124,7 +133,7 @@ def compute_pits(pits, outlets, active_nodes, nbasins):
@
numba
.
njit
def
_connect_basins
(
conn_basins
,
conn_nodes
,
conn_weights
,
nbasins
,
basins
,
outlets
,
receivers
,
stack
,
active_nodes
,
elevation
,
nx
,
ny
):
active_nodes
,
elevation
,
nx
,
ny
,
directions
=
8
):
"""Connect adjacent basins together through their lowest pass.
Creates an (undirected) graph of basins and their connections.
...
...
@@ 173,8 +182,8 @@ def _connect_basins(conn_basins, conn_nodes, conn_weights,
iactive
=
False
# king (D4) neighbor lookup
dr
=
(
0
,

1
,
1
,
0
)
dc
=
(

1
,
0
,
0
,
1
)
dr
=
(
0
,

1
,
1
,
0
,
1
,
1
,

1
,

1
)
dc
=
(

1
,
0
,
0
,
1
,
1
,

1
,
1
,

1
)
for
istack
in
stack
:
irec
=
receivers
[
istack
]
...
...
@@ 201,7 +210,7 @@ def _connect_basins(conn_basins, conn_nodes, conn_weights,
r
=
istack
//
nx
c
=
istack
%
nx
for
k
in
range
(
4
):
for
k
in
range
(
directions
):
kr
=
r
+
dr
[
k
]
kc
=
c
+
dc
[
k
]
...
...
@@ 437,7 +446,7 @@ def _update_pits_receivers(receivers, dist2receivers, outlets,
@
numba
.
njit
def
_sediment_lakes
(
sills
,
basin_stack
,
basin_parent
,
basins
,
water_height
,
elevation
,
sediment_slope
,
nx
,
ny
,
dx
,
dy
):
def
_sediment_lakes
(
sills
,
basin_stack
,
basin_parent
,
basins
,
water_height
,
elevation
,
sediment_slope
,
nx
,
ny
,
dx
,
dy
,
directions
=
8
):
""" Parse the basins from sea to crests, filling each of the basin
by looking at each of the basin nodes, sorted by distance to the sill
...
...
@@ 475,7 +484,7 @@ def _sediment_lakes(sills, basin_stack, basin_parent, basins, water_height, elev
parse_begin
+=
1
for
nb_dir_i
in
range
(
8
):
for
nb_dir_i
in
range
(
directions
):
kr
=
i_node
//
nx
+
dr
[
nb_dir_i
]
kc
=
i_node
%
nx
+
dc
[
nb_dir_i
]
...
...
@@ 505,7 +514,9 @@ def correct_flowrouting(receivers, dist2receivers, ndonors, donors,
active_nodes
,
elevation
,
nx
,
ny
,
dx
,
dy
,
method
=
'mst_linear'
,
sediment_lakes
=
False
,
sediment_slope
=
1e10
,
water_height
=
None
,
reorder
=
True
):
reorder
=
True
,
randomize
=
True
,
directions
=
8
):
"""Ensure that no flow is captured in sinks.
If needed, update `receivers`, `dist2receivers`, `ndonors`,
...
...
@@ 527,14 +538,14 @@ def correct_flowrouting(receivers, dist2receivers, ndonors, donors,
nconn
,
basin0
=
_connect_basins
(
conn_basins
,
conn_nodes
,
conn_weights
,
nbasins
,
basins
,
outlets
,
receivers
,
stack
,
active_nodes
,
elevation
,
nx
,
ny
)
active_nodes
,
elevation
,
nx
,
ny
,
directions
)
#resize conn arrays, applying a random shuffle:
# In case of basins with equal height sills (flat area or 1 sized localminima),
# the resulting connection order in the mst will depend on the order of conn_basins
# Another way to see that is that MST is not unique when some edges has the same weigth,
# in this case we chose the most 'natural' random one
perm
=
np
.
random
.
permutation
(
nconn
)
perm
=
np
.
random
.
permutation
(
nconn
)
if
randomize
else
np
.
arange
(
nconn
)
conn_basins
=
conn_basins
[
perm
]
conn_nodes
=
conn_nodes
[
perm
]
conn_weights
=
conn_weights
[
perm
]
...
...
@@ 567,17 +578,18 @@ def correct_flowrouting(receivers, dist2receivers, ndonors, donors,
water_height
=
np
.
empty_like
(
elevation
)
water_height
[:]
=
elevation
[:]
_sediment_lakes
(
sills
,
basin_stack
[:
basin_stack_size
],
basin_parent
,
basins
,
water_height
,
elevation
,
sediment_slope
,
nx
,
ny
,
dx
,
dy
)
_sediment_lakes
(
sills
,
basin_stack
[:
basin_stack_size
],
basin_parent
,
basins
,
water_height
,
elevation
,
sediment_slope
,
nx
,
ny
,
dx
,
dy
,
directions
)
# the water height obtained from _sediment_lakes is a very regular geometric shape.
# we apply some ramdomness to obtin a more natural drainage pattern,
# without adding any other local minima
water_height
+=
0.99
*
sediment_slope
*
np
.
random
.
rand
(
nx
*
ny
)
*
(
water_height
>
elevation
)
if
randomize
:
water_height
+=
0.99
*
sediment_slope
*
np
.
random
.
rand
(
nx
*
ny
)
*
(
water_height
>
elevation
)
if
reorder
:
reset_receivers
(
receivers
,
nnodes
)
compute_receivers
_d8
(
receivers
,
dist2receivers
,
water_height
,
active_nodes
,
nx
,
ny
,
dx
,
dy
)
compute_receivers
(
receivers
,
dist2receivers
,
water_height
,
active_nodes
,
nx
,
ny
,
dx
,
dy
,
directions
)
else
:
_update_pits_receivers
(
receivers
,
dist2receivers
,
outlets
,
...
...
@@ 590,7 +602,10 @@ def correct_flowrouting(receivers, dist2receivers, ndonors, donors,
def
compute_water_level
(
elevation
,
nx
,
ny
,
dx
,
dy
,
water_height
,
active_nodes
=
None
,
method
=
'mst_linear'
,
sediment_slope
=
1e10
):
def
compute_water_level
(
elevation
,
nx
,
ny
,
dx
,
dy
,
water_height
,
active_nodes
=
None
,
method
=
'mst_linear'
,
sediment_slope
=
1e10
,
randomize
=
True
,
directions
=
8
):
""" Gives, in 'water_height', the elevation of water for a dem 'elevation' of size (nx, ny).
The water level can be given a small slope 'sediment_slope' from the sill, in which case
...
...
@@ 620,8 +635,8 @@ def compute_water_level(elevation, nx, ny, dx, dy, water_height, active_nodes =
active_nodes
=
mask
.
flatten
()
reset_receivers
(
receivers
,
nnodes
)
compute_receivers
_d8
(
receivers
,
dist2receivers
,
elevation
,
active_nodes
,
nx
,
ny
,
dx
,
dy
)
compute_receivers
(
receivers
,
dist2receivers
,
elevation
,
active_nodes
,
nx
,
ny
,
dx
,
dy
,
directions
)
compute_donors
(
ndonors
,
donors
,
receivers
,
nnodes
)
compute_stack
(
stack
,
ndonors
,
donors
,
receivers
,
nnodes
)
...
...
@@ 636,4 +651,8 @@ def compute_water_level(elevation, nx, ny, dx, dy, water_height, active_nodes =
method
=
method
,
sediment_lakes
=
True
,
sediment_slope
=
sediment_slope
,
water_height
=
water_height
,
reorder
=
False
)
reorder
=
False
,
randomize
=
randomize
,
directions
=
directions
)
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