Dear Manuel,
This is R. There is no "it is possible". Only "how" ;-).
For example, with spatstat.geom,
A <- tess(xgrid=seq(0,80, by=8),ygrid=seq(0,80, by=8))
B <- tess(xgrid=seq(0,80, by=4),ygrid=seq(0,80, by=4))
C <- tess(xgrid=seq(0,80, by=2),ygrid=seq(0,80, by=2))
D <- tess(xgrid=seq(0,80, by
Thank you very much Marcelino.
And how can overimpose those grids to a spatial polygon?
Manuel
On Fri, 10 Feb 2023 at 03:09 Marcelino de la Cruz Rot <
marcelino.delac...@urjc.es> wrote:
> Dear Manuel,
> This is R. There is no "it is possible". Only "how" ;-).
>
> For example, with spatstat.geom
It depends on what you mean by "overimpose".
Maybe this way?
# some spatial polygon
library(maptools)
R <- as(affine(letterR, mat=diag(c(20,20))), "SpatialPolygons")
plot(R, border="blue")
# "overimpose" grids A to C on R:
plot(C, border="green", add=T)
plot(B, border="red", add=T)
plot(A, add=
Thank you very much Marcelino.
Manuel
El vie, 10 feb 2023 a las 7:29, Marcelino de la Cruz Rot (<
marcelino.delac...@urjc.es>) escribió:
> It depends on what you mean by "overimpose".
>
> Maybe this way?
>
> # some spatial polygon
> library(maptools)
> R <- as(affine(letterR, mat=diag(c(20,20)))
On Fri, 10 Feb 2023, Marcelino de la Cruz Rot wrote:
It depends on what you mean by "overimpose".
Maybe this way?
# some spatial polygon
Please, in the spirit of the evolving r-spatial package ecosystem
(maptools will retire during 2023):
library(sf)
R <- st_as_sf(affine(letterR, mat=diag
Thank you very much Roger.
Manuel
El vie, 10 feb 2023 a las 8:13, Roger Bivand ()
escribió:
> On Fri, 10 Feb 2023, Marcelino de la Cruz Rot wrote:
>
> > It depends on what you mean by "overimpose".
> >
> > Maybe this way?
> >
> > # some spatial polygon
>
> Please, in the spirit of the evolving r
Dear list members,
I am trying to "crop" a polygon (grid) with a polygon, but the result is an
sf object Geometry type: GEOMETRY, instead of an sf object Geometry type:
POLYGON.
How can I obtain an sf POLYGON?
nc = st_read(system.file("shape/nc.shp", package="sf"))
nc <- st_transform(nc, 3857
Dear Manuel,
technically, the result of st_intersection(x, y), where both x and y are
POLYGONs, can be POINT, LINESTRING, POLGYON and GEOMETRY as well. The
result is GEOMETRY if the type of the different features is not the same
(e.g. POLYGON+POINT).
You can subset the result in this way:
g_2
Manuel, I think you're looking for an intersect*s* rather than the
intersection. Is the following what you're after?
nc = st_read(system.file("shape/nc.shp", package="sf"))
nc <- st_transform(nc, 3857)
g_5 <- st_make_grid(nc, cellsize = 5) |> st_as_sf()
g_5 <- g_5[nc, ]
g_5_d
El 10/02/2023 a las 15:13, Roger Bivand escribió:
On Fri, 10 Feb 2023, Marcelino de la Cruz Rot wrote:
It depends on what you mean by "overimpose".
Maybe this way?
# some spatial polygon
Please, in the spirit of the evolving r-spatial package ecosystem
(maptools will retire during 2023):
Hello all
I'm struggling with a projection system used by miners in South Africa, the Lo
Cape system. I've put together some commented dummy code that I hope
illustrates the issues. If someone could give me some guidance on how to
convert between this and other crs's, that would be much appreci
Thnak you very much Bede-Fazekas.
I got the following error:
g_25000_c_polygons_only <- g_25000_c[st_is(x = g_25000_c, type = "POLYGON")]
Error in `[.data.frame`(x, i) : undefined columns selected
El vie, 10 feb 2023 a las 11:53, Bede-Fazekas Ákos ()
escribió:
> Dear Manuel,
>
> technically, t
Thank you very much Josiah.
If I ran the code you suggested me, How I get the g_25000 object (a grid)?
index <- which(lengths(st_intersects(g_5, nc)) > 0)
plot(st_union(g_5[index,]))
El vie, 10 feb 2023 a las 12:10, Josiah Parry ()
escribió:
> Manuel, I think you're looking for an int
Thank you very much Marcelino.
Manuel
El vie, 10 feb 2023 a las 13:00, Marcelino de la Cruz Rot (<
marcelino.delac...@urjc.es>) escribió:
> El 10/02/2023 a las 15:13, Roger Bivand escribió:
> > On Fri, 10 Feb 2023, Marcelino de la Cruz Rot wrote:
> >
> >> It depends on what you mean by "overimpo
g_25000_c_polygons_only <- g_25000_c[st_is(x = g_25000_c, type = "POLYGON"),] #
with a comma
El 10/02/2023 a las 21:33, Manuel Spínola escribió:
Thnak you very much Bede-Fazekas.
I got the following error:
g_25000_c_polygons_only <- g_25000_c[st_is(x = g_25000_c, type = "POLYGON")]
Error
Thank you very much Marcelino.
That works.
I also find that this works (with terra):
g_25000_c <- crop(vect(g_25000), vect(g_5_d))
g_25000_c <- st_as_sf(g_25000_c)
El vie, 10 feb 2023 a las 15:06, Marcelino de la Cruz Rot (<
marcelino.delac...@urjc.es>) escribió:
>
> g_25000_c_polygons_o
One way is to write it to a (COG) GeoTIFF with overviews ("pyramid", or
zoom levels) - these are pre-calculated copies of the highest resolution
data saved as lower resolution versions.
Do you want this to generate a set of nested data, or is it more about
working with the nested logic?
I'm not s
Oh, with a COG you'd also want control over reading a particular level -
I'm not sure how well that's supported in the "R spatial" realm but I'll
include it in my example, you can always generate VRT to get exactly what
you want from terra and friends.
Cheers, Mike
On Sat, Feb 11, 2023 at 9:36 A
I ran into this a few months ago while preparing for a workshop I gave
(online) to SASA22 participants in South Africa:
https://edzer.github.io/SASA22/workshop.html
If you divide the geometry by -1 (or multiply it by -1) I don't think
you can simply set back the CRS to the old value (EPSG:2228
Thank you very much Michael.
My idea is to create a spatial nested grid to conduct spatial surveys for a
monitoring protocol.
I am thinking to create an 8km, 4km, 2km and 1km nested grids so you can
use different tiles according to the desired resolution of species
occurrences, landscape metrics,
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