Retrieve options used in bcdata, their value if set and the default value.
Source:R/bcdc_options.R
bcdc_options.Rd
This function retrieves bcdata specific options that can be set. These options can be set
using option({name of the option} = {value of the option})
. The default options are purposefully
set conservatively to hopefully ensure successful requests. Resetting these options may result in
failed calls to the data catalogue. Options in R are reset every time R is re-started. See examples for
addition ways to restore your initial state.
Details
bcdata.max_geom_pred_size
is the maximum size in bytes of an object used for a geometric operation. Objects
that are bigger than this value will have a bounding box drawn and apply the geometric operation
on that simpler polygon. The bcdc_check_geom_size function can be used to assess whether a given spatial object
exceed the value of this option. Users can iteratively try to increase the maximum geometric predicate size and see
if the bcdata catalogue accepts the request.
bcdata.chunk_limit
is an option useful when dealing with very large data sets. When requesting large objects
from the catalogue, the request is broken up into smaller chunks which are then recombined after they've
been downloaded. This is called "pagination". bcdata does this all for you but using this option you can set the size of the chunk
requested. On faster internet connections, a bigger chunk limit could be useful while on slower connections,
it is advisable to lower the chunk limit. Chunks must be less than 10000.
bcdata.single_download_limit
is the maximum number of records an object can be before forcing a paginated download
(see entry for bcdata.chunk_limit
for details on pagination).
Tweaking this option in conjunction with bcdata.chunk_limit
can often resolve failures in large and complex downloads.
The default is 10000 records.
Examples
# \donttest{
## Save initial conditions
try(
original_options <- options()
)
## See initial options
try(
bcdc_options()
)
#> # A tibble: 3 × 3
#> option value default
#> <chr> <dbl> <dbl>
#> 1 bcdata.max_geom_pred_size NA 500000
#> 2 bcdata.chunk_limit NA 1000
#> 3 bcdata.single_download_limit 10000 10000
try(
options(bcdata.max_geom_pred_size = 1E6)
)
## See updated options
try(
bcdc_options()
)
#> # A tibble: 3 × 3
#> option value default
#> <chr> <dbl> <dbl>
#> 1 bcdata.max_geom_pred_size 1000000 500000
#> 2 bcdata.chunk_limit NA 1000
#> 3 bcdata.single_download_limit 10000 10000
## Reset initial conditions
try(
options(original_options)
)
# }