prevR (version 3.3)

as.prevR: Create an object of class prevR.

Description

This function creates an object of class prevR from a data frame.

Usage

as.prevR(data, col, boundary = NULL, proj = "+proj=longlat +ellps=WGS84")

Arguments

data

data frame, each line corresponding to an observed cluster.

col

vector identifying the columns of data to use. clusters columns names are fixed:

• "id" (optional) cluster's identifier.

• "x" cluster's longitude.

• "y" cluster's latitude.

• "n" number of valid observations in the cluster.

• "pos" number of positive cases in the cluster.

• "wn" (optional) sum of observations weight.

• "wpos" (optional) sum of positive cases weight.

• "c.type" (optional) type of cluster (used only by plot).

See examples.

boundary

object of class SpatialPolygons defining the studied area.

proj

projection of clusters coordinates used in data (longitude and latitude in decimal degrees by default).

Value

Object of class prevR (see prevR-class for more details)

Details

Only "x", "y" "n" and "pos" are required in col. If "id" is not specified, a numzrical identifier will be automatically created.

proj defines projection used by data. It could be a character string corresponding to a PROJ.4 projection (see http://trac.osgeo.org/proj/ for more details) or an object of class CRS{sp}. If the projection of boundary is defined in a slot called proj4string, boundary will be projected according to proj. If the slot proj4string is missing, boundary will be considered to be already in the same projection as proj.

If boundary is not defined (NULL), a considered corresponding to minimal and maximal coordinates of data will be used. boundary could be the result of the function create.boundary.

It's not possible to change projection of data with as.prevR. Use changeproj instead.

See Also

prevR-class, create.boundary, changeproj, import.dhs.

Examples

# NOT RUN {
 col <- c(id = "cluster",
          x = "x",
          y = "y",
          n = "n",
          pos = "pos",
          c.type = "residence",
          wn = "weighted.n",
          wpos = "weighted.pos"
 )
 dhs <- as.prevR(fdhs.clusters,col, fdhs.boundary)
 
 str(dhs)
 print(dhs)
# }