Polygonizing single cell/single col rasters leads to errors/warnings

[frousseu]

Hello!

I noticed that using polygonize on a single cell raster leads to an error. With a single column raster, it leads to a warning. Below is an example. This is with spex 0.7.1. Thanks!

library(raster)
library(sf)
library(spex)
 
r<-setValues(raster(ncol=1,nrow=1),1)
polygonize(r)

## Error in seq_len(ncol(IB)) : 
##  argument must be coercible to non-negative integer
## In addition: Warning messages:
## 1: In rbind(aa, aa[2:1, ]) :
## number of columns of result is not a multiple of vector length (arg 2)
## 2: In c(rbind(aa, aa[2:1, ])) + c(0, 0, nc1, nc1) :
##  longer object length is not a multiple of shorter object length
## 3: In seq_len(ncol(IB)) : first element used of 'length.out' argument
 
r<-setValues(raster(ncol=1,nrow=2),1)
polygonize(r)

## Simple feature collection with 2 features and 1 field
## geometry type:  POLYGON
## dimension:      XY
## bbox:           xmin: -180 ymin: -90 xmax: 180 ymax: 90
## CRS:            +proj=longlat +datum=WGS84 +no_defs
##  layer                       geometry
## 1     1 POLYGON ((-180 90, 180 90, ...
## 2     1 POLYGON ((-180 0, 180 0, 18...
## Warning messages:
## 1: In rbind(aa, aa[2:1, ]) :
##   number of columns of result is not a multiple of vector length (arg 2)
## 2: In c(rbind(aa, aa[2:1, ])) + c(0, 0, nc1, nc1) :
##   longer object length is not a multiple of shorter object length
 
r<-setValues(raster(ncol=2,nrow=1),1)
polygonize(r)

## Simple feature collection with 2 features and 1 field
## geometry type:  POLYGON
## dimension:      XY
## bbox:           xmin: -180 ymin: -90 xmax: 180 ymax: 90
## CRS:            +proj=longlat +datum=WGS84 +no_defs
##   layer                       geometry
## 1     1 POLYGON ((-180 90, 0 90, 0 ...
## 2     1 POLYGON ((0 90, 180 90, 180...

r<-setValues(raster(ncol=2,nrow=2),1)
polygonize(r)

## Simple feature collection with 4 features and 1 field
## geometry type:  POLYGON
## dimension:      XY
## bbox:           xmin: -180 ymin: -90 xmax: 180 ymax: 90
## CRS:            +proj=longlat +datum=WGS84 +no_defs
##   layer                       geometry
## 1     1 POLYGON ((-180 90, 0 90, 0 ...
## 2     1 POLYGON ((0 90, 180 90, 180...
## 3     1 POLYGON ((-180 0, 0 0, 0 -9...
## 4     1 POLYGON ((0 0, 180 0, 180 -...

[mdsumner]

Thanks, actually thought this had been fixed will check ,👍