Reclassify neighbors

Evaluate if members of two classes are contiguous and, if they are, one of them is reclassified.

reclass.nbs(
  attTbl,
  ngbList,
  rNumb = FALSE,
  classVector,
  nbs_of,
  class,
  reclass,
  reclass_all = TRUE
)

Arguments

attTbl: data.frame, the attribute table returned by the function attTbl.
ngbList: list, the list of neighborhoods returned by the function ngbList.
rNumb: logic, the neighborhoods of the argument ngbList are identified by cell numbers (rNumb=FALSE) or by row numbers (rNumb=TRUE) (see ngbList). It is advised to use row numbers for large rasters.
classVector: numeric vector, defines the cells in the attribute table that have already been classified. See conditions for more information about class vectors.
nbs_of: numeric or numeric vector, indicates the class(es) of focal and anchor cells.
class: numeric or numeric vector, cells of classes class adjacent to cells belonging to one of the classes of nbs_of are reclassified as indicated by the argument reclass.
reclass: numeric, the classification number to assign to all cells that meet the function conditions.
reclass_all: logic, all cells of class class are also reclassified if they are connected to a reclassified cell.

Value

Update classVector with the new cells that were classified by the function. See conditions for more information about class vectors.

Details

The function evaluates if a cell of class class is adjacent to a cell of class nbs_of and, if it is, it is reclassifies as indicated by the argument reclass.
If the argument reclass_all = TRUE, all cells of class class are also reclassified if they are connected to a reclassified cell.

Examples

library(scapesClassification)
library(terra)

# LOAD THE DUMMY RASTER
r <- list.files(system.file("extdata", package = "scapesClassification"),
                pattern = "dummy_raster\\.tif", full.names = TRUE)
r <- terra::rast(r)

# COMPUTE THE ATTRIBUTE TABLE
at <- attTbl(r, "dummy_var")

# COMPUTE THE LIST OF NEIGBORHOODS
nbs <- ngbList(r)

################################################################################
# RECLASS.NBS
################################################################################

# Compute an inital class vector with `cond.4.all`
cv <- cond.4.all(attTbl = at, cond = "dummy_var > 5", class = 1)

# Update the class vector with a second class
cv <- cond.4.all(attTbl = at, cond = "dummy_var >= 2", class = 2,
                 classVector = cv)


# Reclassify cells of class 2 adjacent to cells of class 1

# reclass_all = FALSE
rc1 <- reclass.nbs(attTbl = at, ngbList = nbs,

                   # CLASS VECTOR `cv`
                   classVector = cv,

                   # CELLS OF CLASS...
                   class = 2,

                   # ...ADJACENT TO CELLS OF ANOTHER CLASS...
                   nbs_of = 1,

                   # ...WILL BE RECLASSIFIED...
                   reclass = 3,

                   # NO MORE RECLASSIFICATIONS
                   reclass_all = FALSE)

# reclass_all = TRUE
rc2 <- reclass.nbs(attTbl = at, ngbList = nbs,

                   # CLASS VECTOR `cv`
                   classVector = cv,

                   # CELLS OF CLASS...
                   class = 2,

                   # ...ADJACENT TO CELLS OF ANOTHER CLASS...
                   nbs_of = 1,

                   # ...WILL BE RECLASSIFIED...
                   reclass = 3,

                   # ...AND SO ALL CELLS OF CLASS 1 CONNECTED TO A RECLASSIFIED CELL
                   reclass_all = TRUE)

# Convert class vectors to rasters
r_cv  <- cv.2.rast(r, at$Cell,classVector = cv, plot = FALSE)
r_rc1 <- cv.2.rast(r, at$Cell,classVector = rc1, plot = FALSE)
r_rc2 <- cv.2.rast(r, at$Cell,classVector = rc2, plot = FALSE)

################################################################################
# PLOTS
################################################################################
oldpar <- par(mfrow = c(2,2))
m = c(0.1, 3.5, 3.2, 3.5)


# 1)
plot(r_cv, type="classes", axes=FALSE, legend = FALSE, asp = NA, mar=m,
     colNA="#818792", col=c("#1088a0", "#78b2c4"))
text(r)
mtext(side=3, line=2, adj=0, cex=1, font=2, "COND.4.ALL")
mtext(side=3, line=1, adj=0, cex=0.9, "Step1: 'dummy_var > 5', class: 1")
mtext(side=3, line=0, adj=0, cex=0.9, "Step2: 'dummy_var > 3', class: 2")
legend("bottomright", ncol = 1, bg = "white", y.intersp= 1.2,
       legend = c("Class 1", "Class 2", "Unclassified cells"),
      fill = c("#1088a0", "#78b2c4", "#818792"))

# 2)
plot(r_rc1, type="classes", axes=FALSE, legend = FALSE, asp = NA, mar=m,
     colNA="#818792", col=c("#1088a0", "#78b2c4", "#cfad89"))
text(r)
mtext(side=3, line=2, adj=0, cex=1, font=2, "RECLASS.NBS")
mtext(side=3, line=1, adj=0, cex=0.9, "Reclass: class 2 adjacent to class 1")
mtext(side=3, line=0, adj=0, cex=0.9, "reclass_all = FALSE")
legend("bottomright", ncol = 1, bg = "white", y.intersp= 1.2,
       legend = c("Reclassified cells"), fill = c("#cfad89"))

# 3)
plot(r_rc2, type="classes", axes=FALSE, legend = FALSE, asp = NA, mar=m,
     colNA="#818792", col=c("#1088a0", "#78b2c4", "#cfad89"))
text(r)
mtext(side=3, line=2, adj=0, cex=1, font=2, "RECLASS.NBS")
mtext(side=3, line=1, adj=0, cex=0.9, "Reclass: class 2 adjacent to class 1")
mtext(side=3, line=0, adj=0, cex=0.9, "reclass_all = TRUE")
legend("bottomright", ncol = 1, bg = "white", y.intersp= 1.2,
       legend = c("Reclassified cells"), fill = c("#cfad89"))
par(oldpar)

Arguments

Value

Details

See also

Examples