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Paxman

Coordinates

Canonicalizes one WGS 84 coordinate mention per call — a decimal pair, hemisphere-marked pair, DMS/DDM pair, geo: URI, ISO 6709 string, or GeoJSON lon-first pair (with optional altitude on the carriers) — to a signed lat-first decimal pair.

In plain language: give it 48.8566, 2.3522, 40° 26′ 46″ N 79° 58′ 56″ W, geo:48.8566,2.3522, +48.8577+002.2950/, or [2.295, 48.8577] and it hands back 48.8566, 2.3522 (and friends) when the shape is a real WGS 84 point per ISO 6709:2022 §6, RFC 5870 §3.3, or RFC 7946 §3.1.1. Latitude must land in [-90, 90], longitude in [-180, 180]; a foreign CRS label is rejected, never silently re-datumed.

What it recognizes — and what it does not

Section titled “What it recognizes — and what it does not”
RecognizesDoes not recognize
Decimal pairs with ,, ;, /, or marked-whitespace separators (48.8566, 2.3522, 41.5;-81.0, +40.446 -79.982, parenthesized (41.5, -81.0))Bare prose number runs (pages 12 40) and dotted quads (192.168.1.1) → MISSING
Hemisphere letters, front or back, any case (N 48.8566, E 2.3522, 41.5 N 81.0 W)Contradictory sign plus hemisphere (-41.5 N, -81.0 W) → INVALID
DMS (40° 26′ 46″ N 79° 58′ 56″ W, ASCII 23 26' 22" N 23 27' 30" E) and DDM (40° 26.767′ N 79° 58.933′ W)Unit overflow (40° 70′ 0″ N …, minutes ≥ 60) → INVALID
geo: URIs with optional altitude and explicit WGS 84 CRS (geo:48.8577,2.295,350, geo:48.8566,2.3522;crs=wgs84, crs=WGS_84 also accepted)Foreign CRS (geo:48.8566,2.3522;crs=ed50) → INVALID — no silent datum transform
ISO 6709 strings, degree or DM/DMS widths, with optional altitude (+48.8577+002.2950/, +48.8577+002.2950+350/)Missing Annex H solidus (+48.8577+002.2950) → INVALID
GeoJSON lon-first pairs, inverted losslessly ([2.295, 48.8577], [2.295, 48.8577, 350])Out-of-range envelopes (91.0, 0.0, 0.0, 181.0) → INVALID
Up to 7 fraction digits, quantized to the 6 dp canonical quantum8+-digit fractions (48.85660005, 2.3522) → MISSING

Canonical output

Section titled “Canonical output”

Default output_format is "decimal" (identity — normalize() returns the lat-first pair lat, lon[, alt]).

output_formatRendersExample
(default) decimal / None / "default"Signed lat-first pair, 6 dp round-half-even, trailing zeros stripped, -0 folded to 048.8566, 2.3522
iso6709ISO 6709 Annex H string expression, fraction padded to 4 places (encoding)+48.8566+002.3522/
geo_uriRFC 5870 geo: URI (encoding)geo:48.8566,2.3522
geojson_pairRFC 7946 lon-first pair (encoding)[2.3522, 48.8566]
dmsDegrees-minutes-integer-seconds (documented quantization, 1″ render quantum)48°51′24″N 2°21′8″E
dmDegrees-decimal-minutes to 0.001′ (documented quantization)48°51.396′N 2°21.132′E

Quantization is observable: 48.8566005, 2.0 canonicalizes to 48.8566, 2 while 48.8566015, 2.0 rounds half-even up to 48.856602, 2; -0.0, -0.0 folds to 0, 0. Altitude, when present, rides along in every format (geo:48.8577,2.295,350 → +48.8577+002.2950+350/, geo:48.8577,2.295,350, [2.295, 48.8577, 350], …E, 350). dms/dm drop sub-quantum digits, so re-canonicalizing a dms rendering is a fixed point that drifts within half a render quantum — never stored as canonical.

Any other value raises ContractError — including utm, which this capability has never offered (there is no silent datum transform to project onto).

from paxman.capabilities import Coordinates
import paxman


paxman.register_all_shipped()
print(paxman.canonicalize("48.8566, 2.3522", Coordinates.create_contract()).canonicalized_value)
print(paxman.canonicalize("40° 26′ 46″ N 79° 58′ 56″ W", Coordinates.create_contract()).canonicalized_value)
print(paxman.canonicalize("geo:48.8566,2.3522", Coordinates.create_contract()).canonicalized_value)
print(paxman.canonicalize("+48.8577+002.2950/", Coordinates.create_contract()).canonicalized_value)
print(paxman.canonicalize("[2.295, 48.8577]", Coordinates.create_contract()).canonicalized_value)
print(paxman.canonicalize("48.8566, 2.3522", Coordinates.create_contract(output_format="iso6709")).canonicalized_value)
print(paxman.canonicalize("48.8566, 2.3522", Coordinates.create_contract(output_format="dms")).canonicalized_value)

Contract

Section titled “Contract”
contract = Coordinates.create_contract(
    output_format=None,  # "decimal" (default), "iso6709", "geo_uri", "geojson_pair", "dms", "dm"
    # plus every common field: suppress_common_words / excluded_rules / pinned_rules / year / extra_grammars
)
  • No grammar toggles: one grammar (coordinates_recognition), four rules (Section 6-coordinate-structure, Section Annex-h-string-expression, Section 3.3-geo-uri-validity, Section 3.1.1-position).
  • year filters by publication_year; e.g., year=2010 drops the ISO 6709:2022 rules → 48.8566, 2.3522 becomes INVALID while geo:48.8566,2.3522 still validates via RFC 5870 (2010).

Statuses

Section titled “Statuses”
InputContractStatusValue / why
48.8566, 2.3522defaultsSUCCESS"48.8566, 2.3522"
40° 26′ 46″ N 79° 58′ 56″ WdefaultsSUCCESS"40.446111, -79.982222" (DMS recognized)
geo:48.8566,2.3522defaultsSUCCESS"48.8566, 2.3522" (RFC 5870)
+48.8577+002.2950/defaultsSUCCESS"48.8577, 2.295" (two ISO rules agree, one value)
[2.295, 48.8577]defaultsSUCCESS"48.8577, 2.295" (lon-first inverted)
hello worldanyMISSINGno coordinate shape
48.85660005, 2.3522anyMISSING8-digit fraction exceeds the 7-digit recognition cap
91.0, 0.0anyINVALIDlatitude outside [-90, 90]
-41.5 N, -81.0 WanyINVALIDsign/hemisphere conflict
40° 70′ 0″ N 79° 0′ 0″ WanyINVALIDminutes ≥ 60
geo:48.8566,2.3522;crs=wgs84defaultsSUCCESS"48.8566, 2.3522" (explicit WGS 84 CRS)
geo:48.8566,2.3522;crs=ed50anyINVALIDforeign CRS, never re-datumed
+48.8577+002.2950anyINVALIDAnnex H solidus missing
48.8566, 2.3522year=2010INVALIDSection 6 rule is 2022, dropped
geo:48.8566,2.3522year=2010SUCCESSRFC 5870 rule is 2010, kept
48.8566, 2.3522output_format="utm"raises ContractErrorformat never offered

One grammar (single_value=True) plus rules that all normalize to the same compact pair yields at most one value, so AMBIGUOUS is unreachable for this capability.

Notebook snippet — normalize a mixed column

Section titled “Notebook snippet — normalize a mixed column”
import paxman
from paxman.capabilities import Coordinates
from paxman.core.domain import Resolution
from paxman.core.errors import ContractError


paxman.register_all_shipped()
contract = Coordinates.create_contract()


rows = [
    "48.8566, 2.3522",
    "40° 26′ 46″ N 79° 58′ 56″ W",
    "40° 26.767′ N 79° 58.933′ W",
    "geo:48.8577,2.295,350",
    "+48.8577+002.2950/",
    "[2.295, 48.8577]",
    "(41.5, -81.0)",
    "48.8566005, 2.0",
    "-0.0, -0.0",
    "91.0, 0.0",
    "-41.5 N, -81.0 W",
    "hello world",
]


for text in rows:
    r = paxman.canonicalize(text, contract)
    val = r.canonicalized_value if r.status == Resolution.SUCCESS else "—"
    rule = r.candidates[0].validation_rule if r.candidates else "—"
    print(f"{text!r:38} → {r.status.value:10} {val!r:28} ({rule})")


try:
    Coordinates.create_contract(output_format="utm")
except ContractError as e:
    print(f"utm → ContractError: {e}")

Provenance

Section titled “Provenance”
  • ISO 6709:2022 §6 Coordinate structure (decimal/DMS/DDM/ISO shapes, sign/hemisphere consistency, lat [-90, 90] / lon [-180, 180]) — Section 6-coordinate-structure
  • ISO 6709:2022 Annex H String expression of a point (trailing solidus, WGS 84 CRS family) — Section Annex-h-string-expression
  • IETF RFC 5870 (2010) §3.3 Geo URI validity (geo: branch, WGS 84 only) — Section 3.3-geo-uri-validity
  • IETF RFC 7946 (2016) §3.1.1 Position (GeoJSON lon-first pair, altitude optional) — Section 3.1.1-position

Each candidate’s validation_rule carries the section, and candidate.provenance[0].publication_year the year.

See also: Execution Result, Provenance, Segmentation.