CRS Projection problems prevent spatial merge in R

Question

Here is an updated sense of where I'm at. I decided to re-read in my data file using ReadOGR.

MyDataFile <- read.csv("reduced1.csv")
class(MyDataFile)
coordinates(MyDataFile)<-~X+Y
class(MyDataFile)

writeOGR(MyDataFile, "Folder", "File", driver = "ESRI Shapefile")
proj4string(MyDataFile)

Checking the CRS at this point gives me 'NA' so I try and assign it

Redefined <- readOGR(dsn="Folder", layer = "File")
proj4string(Redefined) <- CRS("+init=epsg:4326") # WGS 84

[1] "+init=epsg:4326 +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0"

Now for reading in my boundaries file:

Map <-readOGR(".","infuse_dist_lyr_2011")
proj4string(Map)

[1] "+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +datum=OSGB36 +units=m +no_defs +ellps=airy +towgs84=446.448,-125.157,542.060,0.1502,0.2470,0.8421,-20.4894"

So now to transform.

NewMap <- spTransform(Map, proj4string(Redefined))

Answer 1

Try reading the layers using rgdal::readOGR , this reads the projection automatically and is (IMO) more robust that readShapePoly.

Then if needed, run spTransform with one of your layers as the "to" option.