Selecting a portion of the map for encounter rates

[lime-n]

I have implemented code that plots species encounter rate of the Northern Bobwhite onto a map, whilst only displaying data for a small portion of this map. However, the plotted map shows the entire region, in this case North America, I wish for only the area displayed with data to show.

I have been following the code as it is.

This is what it looks like:

What I want it to look like:

[mstrimas]

Again, this is more of a general spatial R questions, but the idea is you either need to:

• use the xlim and ylim arguments to the sf plot function, see ?sf::plot
• or, ensure the first layer you plot has the desired extent, which is what's done in the book with:

  # set up plot area
  plot(bcr, col = NA, border = NA)

[lime-n]

I found that the mistake was at the beginning of the book, which is easily corrected and may have been a simple miss when writing the code.

when reading the bcr code at the beginning:

> bcr <- read_sf("data/gis-data.gpkg", "bcr") %>% 
st_transform(crs = map_proj) %>% 
 st_geometry()

It is best to include:

filter(bcr_code == 27) %>% 

to make sure you filter only the bcr region.

This gives the desired second image above.

[mstrimas]

What "data/gis-data.gpkg" file are you using? The one available for download via the website only includes BCR 27 so you shouldn't need to use filter(bcr_code == 27)

[lime-n]

That makes plenty of sense now! I was using the older gis geopackage that included all of the bcr regions.