Kota Tua

Jakarta Barat · Colonial grid

The seventeenth-century Batavia canal-and-block plan, still legible under the present streets.

Read the two columns below as two readings of the same data rather than as a gap that can yet be concluded from. The gang here are not mapped densely enough for that.

Drive

Fig. 1 · r = 800 m — The drivable network inside the sampling disc. Uniform ink, no road-class hierarchy, no basemap: the shape is the subject.

Drive H 2.934 · φ 0.50

Orientation entropy: 2.934nat
H / H max: 0.819
φ orientation-order: 0.504
Circuity: 1.589~412
Average node degree: 2.24
Four-way: 3.8%
Dead-end: 26.2%
Intersection density: 164 /km²
Median segment length: 34 m
Network length: 44.1 km

H is in nats — the natural-log unit of information. That is why its maximum is ln 36 ≈ 3.584 rather than log₂ 36.

Circuity is an estimate: network distance over straight-line distance, averaged across a seeded sample of node pairs rather than across all of them. 412 pairs sampled · 79 pairs unreachable Pairs with no route between them at all are excluded from the mean. A large count means this network is fragmented — a signal about the data, not about the place.

Where these come from

Nodes: 715
Edges: 800
Intersections (degree ≥ 3): 330
Disc area: 2.01 km²
Intersection density: 164 /km²
Rose weighted length: 88.2 km
Per-edge circuity: 1.024

The intermediate values the column above is built from. Intersection density is the intersection count over the disc area; the weighted length is the denominator that turns a rose bar into a share. Two different circuity measures: the per-edge one compares each segment against its own chord, the sampled one compares distances between junctions. The first measures how much streets bend, the second how far out of your way the network takes you.

Walk

Fig. 2 · r = 800 m — The walkable network at the same centre, the same disc, the same extract. Every difference from the drawing beside it is the tag mapping, not a different place.

Walk H 2.910 · φ 0.52

Orientation entropy: 2.910nat
H / H max: 0.812
φ orientation-order: 0.519
Circuity: 1.445~424
Average node degree: 2.34
Four-way: 6.1%
Dead-end: 23.5%
Intersection density: 235 /km²
Median segment length: 28 m
Network length: 46.7 km

H is in nats — the natural-log unit of information. That is why its maximum is ln 36 ≈ 3.584 rather than log₂ 36.

Circuity is an estimate: network distance over straight-line distance, averaged across a seeded sample of node pairs rather than across all of them. 424 pairs sampled · 67 pairs unreachable Pairs with no route between them at all are excluded from the mean. A large count means this network is fragmented — a signal about the data, not about the place.

Where these come from

Nodes: 924
Edges: 1080
Intersections (degree ≥ 3): 473
Disc area: 2.01 km²
Intersection density: 235 /km²
Rose weighted length: 93.5 km
Per-edge circuity: 1.026

Both roses overlaid

Drive H 2.934 · φ 0.50Walk H 2.910 · φ 0.52

Each street segment’s bearing goes into one of 36 bins of 10°, weighted by length: a 500 m road counts ten times a 50 m gang. Bar length is the share of network length running that way, not a count of segments. The rose is always 180°-symmetric, because one segment traversed both ways differs by exactly 180°. Boeing 2019 §3

Drive
Walk
Both

DeltaWalk − Drive

Orientation entropy: −0.024
H / H max: −0.007
φ orientation-order: +0.015
Circuity: −0.144
Average node degree: +0.10
Four-way: +2.3%
Dead-end: −2.7%
Intersection density: +71
Median segment length: −6
Network length: +2.6

What walking adds

Walk-only length: 7.3 km
Share of walking network: 15.7%

Fig. 3 · r = 800 m — Ink: the edges that exist only in the walking network. Hairline: the network both modes share. Membership is decided by the tag mapping — an edge counts as walk-only when the OSM way it came from is not admitted to the driving network.

Rose as a table — 36 bins — Kota Tua

Share of network length per 10° bearing bin, for drive and walk.
Bin	Bearing range	P — Drive	P — Walk	−P·ln P	−P·ln P
00	355°–5°	1.97%	2.00%	0.0774	0.0783
01	5°–15°	0.60%	0.62%	0.0306	0.0315
02	15°–25°	0.61%	0.75%	0.0311	0.0366
03	25°–35°	0.30%	0.47%	0.0173	0.0252
04	35°–45°	0.32%	0.38%	0.0184	0.0212
05	45°–55°	0.23%	0.27%	0.0137	0.0162
06	55°–65°	0.64%	0.66%	0.0321	0.0330
07	65°–75°	10.77%	11.31%	0.2401	0.2465
08	75°–85°	9.15%	7.24%	0.2188	0.1900
09	85°–95°	1.47%	1.73%	0.0621	0.0702
10	95°–105°	1.52%	0.94%	0.0637	0.0439
11	105°–115°	1.02%	0.63%	0.0468	0.0319
12	115°–125°	2.88%	2.23%	0.1021	0.0849
13	125°–135°	1.15%	1.21%	0.0514	0.0535
14	135°–145°	0.42%	0.42%	0.0229	0.0229
15	145°–155°	0.53%	0.52%	0.0278	0.0275
16	155°–165°	8.27%	10.02%	0.2061	0.2306
17	165°–175°	8.16%	8.59%	0.2044	0.2109
18	175°–185°	1.97%	2.00%	0.0774	0.0783
19	185°–195°	0.60%	0.62%	0.0306	0.0315
20	195°–205°	0.61%	0.75%	0.0311	0.0366
21	205°–215°	0.30%	0.47%	0.0173	0.0252
22	215°–225°	0.32%	0.38%	0.0184	0.0212
23	225°–235°	0.23%	0.27%	0.0137	0.0162
24	235°–245°	0.64%	0.66%	0.0321	0.0330
25	245°–255°	10.77%	11.31%	0.2401	0.2465
26	255°–265°	9.15%	7.24%	0.2188	0.1900
27	265°–275°	1.47%	1.73%	0.0621	0.0702
28	275°–285°	1.52%	0.94%	0.0637	0.0439
29	285°–295°	1.02%	0.63%	0.0468	0.0319
30	295°–305°	2.88%	2.23%	0.1021	0.0849
31	305°–315°	1.15%	1.21%	0.0514	0.0535
32	315°–325°	0.42%	0.42%	0.0229	0.0229
33	325°–335°	0.53%	0.52%	0.0278	0.0275
34	335°–345°	8.27%	10.02%	0.2061	0.2306
35	345°–355°	8.16%	8.59%	0.2044	0.2109
Sum = H				2.934	2.910

The last column is each bin’s term in H = −Σ P(i)·ln P(i). Add the thirty-six of them and you get the H printed under the rose. An empty bin contributes zero.

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Data jalan © OpenStreetMap contributors, ODbL 1.0. Basis data turunan ini ditawarkan dengan lisensi yang sama. · Boeing, G. 2019. Urban Spatial Order: Street Network Orientation, Configuration, and Entropy. Applied Network Science 4(1):67.