| sgo_set_gcs {sgo} | R Documentation |
Set GCS of a set of points
Description
Changes the geodetic coordinate system of a set of points using a single Helmert transformation.
Usage
sgo_set_gcs(x, to = NULL)
Arguments
x |
A |
to |
Specifies the EPSG code to convert the coordinates to. Currently it
can take any of the following values: |
Details
Changes the geodetic coordinate system of a set of points. Note that the precision of various datums will vary, and the original WGS-84 is not defined to be accurate to better than ±1 metre. Most transformations shouldn't be assumed to be accurate to better than a meter; between OSGB36 and WGS84 somewhat less - the lost of accuracy can be up to ±5m when using single Helmert transformations.
Input points with a projected coordinate system (e.g. 27700, 7405, 3035 or 3857) are not allowed.
Warning This function is mainly for internal use of the program. Since it relies on a single Helmert transformation it is not recommended to call it directly. Use any other of the transformation functions available (sgo-package).
Value
An object of class 'sgo_points'.
See Also
Examples
lon <- c(-4.25181,-3.18827)
lat <- c(55.86424, 55.95325)
p <- sgo_points(list(longitude=lon, latitude=lat), epsg=4326)
# warning: a single Helmert transformation is used in the next transformation
p2 <- sgo_set_gcs(p, to=4277)
# if higher precision is required to transform between OSGB36 lon/lat and
# ETRS89/WGS84 lon/lat then use the OSTN15 transformation (will be slower):
# Transform from WGS84 lon/lat coordinates to EPSG:4277 using OSTN15
p2 <- sgo_transform(p, to=4277)