在管道 R 中将 lat/long 坐标突变为 UTM

Question

我有一个海岸线空间值的 df，但它们在 lat/lon，我需要它们在 NAD83/UTM 10N 区。我可以通过在 dplyr 管道中进行变异来做到这一点吗？

testdf <- data.frame(long = c(-124.0048, -123.9844, -123.9691, -123.9604, -123.9810, -123.9612),
                   lat = c(45.04352, 45.10493, 45.20530, 45.29999, 45.34960, 45.40917))


testdf %>% mutate(utm = rgdal::project(c(lon,lat), proj = ???),
# but then I guess I would need to separate the utm column into x and y still.

或者 map()?

编辑：对不起，我现在意识到这是一个糟糕的代表。实际数据集有投影 +proj=longlat +datum=WGS84 +no_defs。现在正在将其编辑到 testdf 中。

Answer 1

您可以使用 sf 包：

library(sf)
#> Linking to GEOS 3.8.0, GDAL 3.0.4, PROJ 6.3.1
testdf <- data.frame(long = c(-124.0048, -123.9844, -123.9691, -123.9604, -123.9810, -123.9612),
                     lat = c(45.04352, 45.10493, 45.20530, 45.29999, 45.34960, 45.40917))

testsf = st_as_sf(testdf, coords = c("long", "lat"))
testsf <- st_set_crs(testsf, "+proj=longlat +datum=WGS84") 
testsf 
#> Simple feature collection with 6 features and 0 fields
#> geometry type:  POINT
#> dimension:      XY
#> bbox:           xmin: -124.0048 ymin: 45.04352 xmax: -123.9604 ymax: 45.40917
#> CRS:            +proj=longlat +datum=WGS84
#>                     geometry
#> 1 POINT (-124.0048 45.04352)
#> 2 POINT (-123.9844 45.10493)
#> 3  POINT (-123.9691 45.2053)
#> 4 POINT (-123.9604 45.29999)
#> 5   POINT (-123.981 45.3496)
#> 6 POINT (-123.9612 45.40917)

utmsf <- st_transform(testsf,"+proj=utm +zone=10 +ellps=GRS80 +datum=NAD83" )
utmsf
#> Simple feature collection with 6 features and 0 fields
#> geometry type:  POINT
#> dimension:      XY
#> bbox:           xmin: 420866.4 ymin: 4988276 xmax: 424783.9 ymax: 5028855
#> CRS:            +proj=utm +zone=10 +ellps=GRS80 +datum=NAD83
#>                   geometry
#> 1 POINT (420866.4 4988276)
#> 2   POINT (422556 4995078)
#> 3 POINT (423893.4 5006214)
#> 4 POINT (424701.9 5016725)
#> 5 POINT (423153.9 5022256)
#> 6 POINT (424783.9 5028855)

^{由 reprex package (v0.3.0)}

于 2020-08-12 创建

关联的管道是：

library(dplyr)
testdf %>% st_as_sf(coords = c("long", "lat")) %>%
           st_set_crs("+proj=longlat +datum=WGS84") %>%
           st_transform("+proj=utm +zone=10 +ellps=GRS80 +datum=NAD83" )

在管道 R 中将 lat/long 坐标突变为 UTM

mutate lat/long coordinates to UTM in a pipe R

r

spatial

utm

coordinates

dplyr