Convert Latitude and Longitude spatial coordinates to TM projection coordinates with a user-defined central meridian.

Source: R/LLtoUTM.R

The resulting units from applying the function are kilometers.

LLtoUTM(cm, lat, lon, xcol = "x", ycol = "y", minx = NULL,
  miny = NULL)

Arguments

cm

is the user defined central median, often taken to be the mean of the longitude values
lat

is the vector of latitudes
lon

is the vector of longitudes
xcol

is the name of the output column of x coordinates
ycol

is the name of the output column of y coordinates
minx

is `NULL` by default
miny

is `NULL` by default

Value

A list with the TM coordinates as the first component of the list. The first component of the list contains x coordinates in the first column and y coordinates in the second column

Details

This function only needs to be used if the coordinates supplied by the user are latitude and longitude. If the coordinates are UTM, then we should not use this function.

Examples

## Add TM x and y coordinates to a data frame with
## latitude/longitude coordinates
exampledataset$xc_TM_ <- LLtoUTM(cm = base::mean(exampledataset[ ,"xcoords"]),
 lat = exampledataset[ ,"ycoords"],
 lon = exampledataset[ ,"xcoords"])$xy[ ,1]
exampledataset$yc_TM_ <- LLtoUTM(cm = base::mean(exampledataset[ ,"xcoords"]),
 lat = exampledataset[ ,"ycoords"],
 lon = exampledataset[ ,"xcoords"])$xy[ ,2]