Create SpatialPointsDataframe

Question

I have a dataframe df1 with 10 columns. Two of these columns are lng and lat. I want to create a SpatialPointsDataframe f

Answer 1

To make a SpatialPointsDataFrame you need 3 components:

1. coordinates
2. data
3. proj4string of the coordinates (AKA, coordinate reference system (CRS))

---

# load some example data
library(sp)                       # spatial library
data(meuse)                       # load built in dataset

# prepare coordinates, data, and proj4string
coords <- meuse[ , c("x", "y")]   # coordinates
data   <- meuse[ , 3:14]          # data
crs    <- CRS("+init=epsg:28992") # proj4string of coords

# make the SpatialPointsDataFrame object
spdf <- SpatialPointsDataFrame(coords      = coords,
                               data        = data, 
                               proj4string = crs)

---

# check the object class
class(spdf)

[1] "SpatialPointsDataFrame"
attr(,"package")
[1] "sp"

# plot the copper column 
spplot(spdf, "copper")