srs_convert | R Documentation |
These functions convert various spatial reference formats to Well Known Text (WKT) or PROJJSON.
epsg_to_wkt(epsg, pretty = FALSE)
srs_to_wkt(srs, pretty = FALSE, gcs_only = FALSE)
srs_to_projjson(
srs,
multiline = TRUE,
indent_width = 2L,
schema = NA_character_
)
epsg |
Integer EPSG code. |
pretty |
Logical value. |
srs |
Character string containing an SRS definition in various formats (see Details). |
gcs_only |
Logical value. |
multiline |
Logical value. |
indent_width |
Integer value. Defaults to |
schema |
Character string containing URL to PROJJSON schema. Can be set to empty string to disable it. |
epsg_to_wkt()
exports the spatial reference for an EPSG code to
WKT format.
Wrapper for OSRImportFromEPSG()
in the GDAL Spatial Reference System API
with output to WKT.
srs_to_wkt()
converts a spatial reference system (SRS) definition
in various text formats to WKT. The function will examine the input SRS,
try to deduce the format, and then export it to WKT.
Wrapper for OSRSetFromUserInput()
in the GDAL Spatial Reference System
API with output to WKT.
srs_to_projjson()
accepts a spatial reference system (SRS) definition in
any of the formats supported by srs_to_wkt()
, and converts into PROJJSON
format. Wrapper for OSRExportToPROJJSON()
in the GDAL Spatial Reference
System API.
The input SRS may take the following forms:
WKT - to convert WKT versions (see below)
EPSG:n - EPSG code n
AUTO:proj_id,unit_id,lon0,lat0 - WMS auto projections
urn:ogc:def:crs:EPSG::n - OGC URNs
PROJ.4 definitions
filename - file to read for WKT, XML or PROJ.4 definition
well known name such as NAD27, NAD83, WGS84 or WGS72
IGNF:xxxx, ESRI:xxxx - definitions from the PROJ database
PROJJSON (PROJ >= 6.2)
srs_to_wkt()
is intended to be flexible, but by its nature it is
imprecise as it must guess information about the format intended.
epsg_to_wkt()
could be used instead for EPSG codes.
As of GDAL 3.0, the default format for WKT export is OGC WKT 1.
The WKT version can be overridden by using the OSR_WKT_FORMAT
configuration option (see set_config_option()
).
Valid values are one of: SFSQL, WKT1_SIMPLE, WKT1, WKT1_GDAL,
WKT1_ESRI, WKT2_2015, WKT2_2018, WKT2, DEFAULT.
If SFSQL, a WKT1 string without AXIS, TOWGS84, AUTHORITY or
EXTENSION node is returned. If WKT1_SIMPLE, a WKT1 string without
AXIS, AUTHORITY or EXTENSION node is returned. WKT1 is an alias of
WKT1_GDAL. WKT2 will default to the latest revision implemented
(currently WKT2_2018). WKT2_2019 can be used as an alias of
WKT2_2018 since GDAL 3.2
Character string containing OGC WKT.
Setting gcs_only = TRUE
in srs_to_wkt()
is a wrapper of
OSRCloneGeogCS()
in the GDAL API. The returned WKT will be for the GEOGCS
node of the input srs
.
srs_query
epsg_to_wkt(5070)
writeLines(epsg_to_wkt(5070, pretty = TRUE))
srs_to_wkt("NAD83")
writeLines(srs_to_wkt("NAD83", pretty = TRUE))
set_config_option("OSR_WKT_FORMAT", "WKT2")
writeLines(srs_to_wkt("NAD83", pretty = TRUE))
set_config_option("OSR_WKT_FORMAT", "")
srs_to_wkt("EPSG:5070", gcs_only = TRUE)
srs_to_projjson("NAD83") |> writeLines()
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