Why does slotNames work on data.frame even though it is not really a S4 object?
1
The code block below...
data(meuse.grid)
isS4(meuse.grid)
slotNames(meuse.grid)
#meuse.grid@names # this will fail
class(meuse.grid)
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
slotNames(meuse.grid)
head(meuse.grid@data)
class(meuse.grid)
...produces the following output:
library(sp)
data(meuse.grid)
isS4(meuse.grid)
#> [1] FALSE
slotNames(meuse.grid)
#> [1] ".Data" "names" "row.names" ".S3Class"
#meuse.grid@names # this will fail
class(meuse.grid)
#> [1] "data.frame"
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
#> [1] TRUE
slotNames(meuse.grid)
#> [1] "data" "coords.nrs" "coords" "bbox" "proj4string"
head(meuse.grid@data)
#> part.a part.b dist soil ffreq
#> 1 1 0 0.0000000 1 1
#> 2 1 0 0.0000000 1 1
#> 3 1 0 0.0122243 1 1
#> 4 1 0 0.0434678 1 1
#> 5 1 0 0.0000000 1 1
#> 6 1 0 0.0122243 1 1
class(meuse.grid)
#> [1] "SpatialPointsDataFrame"
#> attr(,"package")
#> [1] "sp"
Created on 2018-11-24 by the reprex package (v0.2.1)
So it appears slotNames cannot be used to determine if an object really contains slots, but what is the explanation for this behavior?
r dataframe slots
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
add a comment |
1
The code block below...
data(meuse.grid)
isS4(meuse.grid)
slotNames(meuse.grid)
#meuse.grid@names # this will fail
class(meuse.grid)
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
slotNames(meuse.grid)
head(meuse.grid@data)
class(meuse.grid)
...produces the following output:
library(sp)
data(meuse.grid)
isS4(meuse.grid)
#> [1] FALSE
slotNames(meuse.grid)
#> [1] ".Data" "names" "row.names" ".S3Class"
#meuse.grid@names # this will fail
class(meuse.grid)
#> [1] "data.frame"
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
#> [1] TRUE
slotNames(meuse.grid)
#> [1] "data" "coords.nrs" "coords" "bbox" "proj4string"
head(meuse.grid@data)
#> part.a part.b dist soil ffreq
#> 1 1 0 0.0000000 1 1
#> 2 1 0 0.0000000 1 1
#> 3 1 0 0.0122243 1 1
#> 4 1 0 0.0434678 1 1
#> 5 1 0 0.0000000 1 1
#> 6 1 0 0.0122243 1 1
class(meuse.grid)
#> [1] "SpatialPointsDataFrame"
#> attr(,"package")
#> [1] "sp"
Created on 2018-11-24 by the reprex package (v0.2.1)
So it appears slotNames cannot be used to determine if an object really contains slots, but what is the explanation for this behavior?
r dataframe slots
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
add a comment |
1
1
1
1
The code block below...
data(meuse.grid)
isS4(meuse.grid)
slotNames(meuse.grid)
#meuse.grid@names # this will fail
class(meuse.grid)
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
slotNames(meuse.grid)
head(meuse.grid@data)
class(meuse.grid)
...produces the following output:
library(sp)
data(meuse.grid)
isS4(meuse.grid)
#> [1] FALSE
slotNames(meuse.grid)
#> [1] ".Data" "names" "row.names" ".S3Class"
#meuse.grid@names # this will fail
class(meuse.grid)
#> [1] "data.frame"
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
#> [1] TRUE
slotNames(meuse.grid)
#> [1] "data" "coords.nrs" "coords" "bbox" "proj4string"
head(meuse.grid@data)
#> part.a part.b dist soil ffreq
#> 1 1 0 0.0000000 1 1
#> 2 1 0 0.0000000 1 1
#> 3 1 0 0.0122243 1 1
#> 4 1 0 0.0434678 1 1
#> 5 1 0 0.0000000 1 1
#> 6 1 0 0.0122243 1 1
class(meuse.grid)
#> [1] "SpatialPointsDataFrame"
#> attr(,"package")
#> [1] "sp"
Created on 2018-11-24 by the reprex package (v0.2.1)
So it appears slotNames cannot be used to determine if an object really contains slots, but what is the explanation for this behavior?
r dataframe slots
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
The code block below...
data(meuse.grid)
isS4(meuse.grid)
slotNames(meuse.grid)
#meuse.grid@names # this will fail
class(meuse.grid)
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
slotNames(meuse.grid)
head(meuse.grid@data)
class(meuse.grid)
...produces the following output:
library(sp)
data(meuse.grid)
isS4(meuse.grid)
#> [1] FALSE
slotNames(meuse.grid)
#> [1] ".Data" "names" "row.names" ".S3Class"
#meuse.grid@names # this will fail
class(meuse.grid)
#> [1] "data.frame"
coordinates(meuse.grid) = ~x+y
isS4(meuse.grid)
#> [1] TRUE
slotNames(meuse.grid)
#> [1] "data" "coords.nrs" "coords" "bbox" "proj4string"
head(meuse.grid@data)
#> part.a part.b dist soil ffreq
#> 1 1 0 0.0000000 1 1
#> 2 1 0 0.0000000 1 1
#> 3 1 0 0.0122243 1 1
#> 4 1 0 0.0434678 1 1
#> 5 1 0 0.0000000 1 1
#> 6 1 0 0.0122243 1 1
class(meuse.grid)
#> [1] "SpatialPointsDataFrame"
#> attr(,"package")
#> [1] "sp"
Created on 2018-11-24 by the reprex package (v0.2.1)
So it appears slotNames cannot be used to determine if an object really contains slots, but what is the explanation for this behavior?
r dataframe slots
r dataframe slots
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
edited Nov 24 '18 at 12:36
duckmayr
7,77811326
7,77811326
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
asked Nov 24 '18 at 11:25
prusswanprusswan
5,47232750
5,47232750
add a comment |
add a comment |
0
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