slice_head: Subset first rows of 'data_request'

In galah: Biodiversity Data from the GBIF Node Network

Subset first rows of data_request

Description

This is a simple function to set the limit argument in atlas_counts() using dplyr syntax. As of galah 2.0.0, slice_head() is only supported in queries of type occurrences-count(), or metadata requests. Note also that slice_head() is lazily evaluated; it only affects a query once it is run by compute() or (more likely) collect().

Usage

## S3 method for class 'data_request'
slice_head(.data, ..., n, prop, by = NULL)

## S3 method for class 'metadata_request'
slice_head(.data, ..., n, prop, by = NULL)

Arguments

.data	An object of class data_request, created using galah_call()
...	currently ignored
n	The number of rows to be returned. If data are grouped (using group_by), this operation will be performed on each group.
prop	currently ignored, but could be added later
by	currently ignored

Examples

## Not run: 
# Limit number of rows returned to 3.
# In this case, our query returns the top 3 years with most records.
galah_call() |>
  identify("perameles") |>
  filter(year > 2010) |>
  group_by(year) |>
  count() |>
  slice_head(n = 3) |>
  collect()

## End(Not run)

galah documentation built on Nov. 20, 2023, 9:07 a.m.