[R] R count.points thinks projections are different

[Rebecca Wooldridge [bs13rw]]

I am currently working with telemetry data for some cats:


x<-read.csv("CCATS.csv")
obs2<-x[c("ID", "X", "Y")]
dat_df <- obs2 %>% dplyr::select(ID) %>% as.data.frame()
p4s <- "+proj=utm +zone=16 +ellps=clrk66 +datum=NAD27 +units=m +no_defs"
p4s_crs <- CRS(p4s)
xy <- obs2 %>% dplyr::select(X, Y) %>% as.matrix()
xy_sp <- SpatialPointsDataFrame(xy, data = dat_df, proj4string=p4s_crs)

I also have some raster maps of the study area:

> summary(habitat)
Object of class SpatialPixelsDataFrame
Coordinates:
        min       max
x  328048.6  360028.8
y 1841819.0 1874744.0
Is projected: TRUE
proj4string :
[+proj=utm +zone=16 +ellps=clrk66 +datum=NAD27 +units=m +no_defs
+nadgrids=@conus, at alaska, at ntv2_0.gsb, at ntv1_can.dat]
Number of points: 13024
Grid attributes:
   cellcentre.offset cellsize cells.dim
s1          328139.5 181.7057       176
s2         1842041.5 444.9324        74
Data attributes:
   elevation        ecosystem         slope             aspect
 Min.   : 1.000   Min.   : 1.00   Min.   :0.00000   Min.   :  0.0
 1st Qu.: 1.000   1st Qu.:15.00   1st Qu.:0.00000   1st Qu.: 90.0
 Median : 2.000   Median :15.00   Median :0.04134   Median : 90.0
 Mean   : 2.263   Mean   :12.85   Mean   :0.05194   Mean   :132.5
 3rd Qu.: 3.000   3rd Qu.:15.00   3rd Qu.:0.08523   3rd Qu.:180.0
 Max.   :11.000   Max.   :18.00   Max.   :0.35079   Max.   :360.0
 NA's   :18                       NA's   :84        NA's   :84

when i try to use the count.points function i get the following message:

Error in count.points(SpatialPoints(x), w) :
  different proj4string in w and xy

but
> identical(proj4string(habitat), proj4string(xy_sp))
[1] TRUE
 and i have also tried
proj4string(xy_sp) <- proj4string(habitat)
and then running again but i still get the same error message.

Any help would be greatly appreciated.

Becky


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