On Tue, 31 Jan 2023, Steve Gutreuter wrote:
The need to re-scale the measurement units of the coordinates may not
be commonplace, but it is also not unreasonable. So, given that R rgdal
is to be retired in 2023, what is the "correct" way to preserve the new
units and the datum?
Sorry, there
The need to re-scale the measurement units of the coordinates may not
be commonplace, but it is also not unreasonable. So, given that R rgdal
is to be retired in 2023, what is the "correct" way to preserve the new
units and the datum?
Thanks to all,Steve
On Tue, 2023-01-31 at 18:36 +0100, Andrea
Thanks, Roger. That's not a common problem (at least for me), but it
is typically useful to adjust the unit of measurement when I need to
integrate sf objects with other packages (e.g. spatstat) where the
numerical algorithm might benefit from rescaling.
Andrea
Il giorno mar 31 gen 2023 alle ore
On Tue, 31 Jan 2023, Andrea Gilardi wrote:
Thanks again to both of you for the suggestion and the explanation.
Using:
meuse1 <- st_as_sf(meuse)
meuse2 <- st_transform(meuse1, sub("units=m", "units=km",
st_crs(meuse1)$proj4string))
gives
st_crs(meuse2)
Coordinate Reference System:
User
Thanks again to both of you for the suggestion and the explanation.
Kind regards
Andrea
Il giorno mar 31 gen 2023 alle ore 15:28 Edzer Pebesma
ha scritto:
>
> Yes, the pipeline approach bypasses GDAL, and doesn't result in an
> object with an appropriate CRS as a consequence.
>
> On 31/01/2023
Yes, the pipeline approach bypasses GDAL, and doesn't result in an
object with an appropriate CRS as a consequence.
On 31/01/2023 14:47, Andrea Gilardi wrote:
Thank you very much for your example! I briefly checked the examples
reported in ?st_transform and the docs at the PROJ website around
While the package interface isn't the friendliest, I think the crsuggest
package may be of interest for you. It's helpful for finding an appropriate
CRS in the units you need given an input CRS.
https://github.com/walkerke/crsuggest
I've used this to find an appropriate CRS and then transform
Thank you very much for your example! I briefly checked the examples
reported in ?st_transform and the docs at the PROJ website around
"Unit conversion"
(https://proj.org/operations/conversions/unitconvert.html) and I found
that the following code also seems to work (although with a warning
On 31/01/2023 12:12, Andrea Gilardi wrote:
st_transform can do transformations and conversions between different CRSs,
unit conversions is a special case of that.
Dear all, I'm sorry if this is a trivial or stupid question but I was
wondering if you could provide an example of using
> st_transform can do transformations and conversions between different CRSs,
> unit conversions is a special case of that.
Dear all, I'm sorry if this is a trivial or stupid question but I was
wondering if you could provide an example of using st_transform to
apply a unit conversion
On 25/01/2023 18:42, Josiah Parry wrote:
I wonder if `units::set_units()` is a better fit for the job
https://r-quantities.github.io/units/articles/measurement_units_in_R.html
It could definitely tell you which number to choose when going from,
say, US feet to km. Coordinates in sf
I guess the question is: "safe for what?" - if numerical errors are a
problem without rescaling, then you should do it. You might be able to
choose the rescaling factor such that these errors are minimized.
On 25/01/2023 18:37, Steve Gutreuter wrote:
Is it safe to re-scale sf geometry
I wonder if `units::set_units()` is a better fit for the job
https://r-quantities.github.io/units/articles/measurement_units_in_R.html
On Wed, Jan 25, 2023 at 12:37 PM Steve Gutreuter
wrote:
> Is it safe to re-scale sf geometry coordinates from meters to
> kilometers using, for example:
>
>
Is it safe to re-scale sf geometry coordinates from meters to
kilometers using, for example:
sfobj$geometry <- sfobj$geometry / 1000
It seems to work, but I understand too little about spatial data to
know whether that practice is actually safe. I am working with spatial
data in a
14 matches
Mail list logo
