Randomly sample some proportion of observations from a [taxmap()] object. Weights can be specified for observations or their taxa. See [dplyr::sample_frac()] for the inspiration for this function. Calling the function using the `obj$sample_frac_obs(...)` style edits "obj" in place, unlike most R functions. However, calling the function using the `sample_frac_obs(obj, ...)` imitates R's traditional copy-on-modify semantics, so "obj" would not be changed; instead a changed version would be returned, like most R functions.
obj$sample_frac_obs(data, size, replace = FALSE,
taxon_weight = NULL, obs_weight = NULL,
use_supertaxa = TRUE, collapse_func = mean, ...)
sample_frac_obs(obj, data, size, replace = FALSE,
taxon_weight = NULL, obs_weight = NULL,
use_supertaxa = TRUE, collapse_func = mean, ...)An object of type [taxmap()]
([taxmap()]) The object to sample from.
Dataset names, indexes, or a logical vector that indicates which datasets in `obj$data` to sample. If multiple datasets are sample at once, then they must be the same length.
(`numeric` of length 1) The proportion of observations to sample.
(`logical` of length 1) If `TRUE`, sample with replacement.
(`numeric`) Non-negative sampling weights of each taxon. If `use_supertaxa` is `TRUE`, the weights for each taxon in an observation's classification are supplied to `collapse_func` to get the observation weight. If `obs_weight` is also specified, the two weights are multiplied (after `taxon_weight` for each observation is calculated).
(`numeric`) Sampling weights of each observation. If `taxon_weight` is also specified, the two weights are multiplied (after `taxon_weight` for each observation is calculated).
(`logical` or `numeric` of length 1) Affects how the `taxon_weight` is used. If `TRUE`, the weights for each taxon in an observation's classification are multiplied to get the observation weight. If `FALSE` just the taxonomic level the observation is assign to it considered. Positive numbers indicate the number of ranks above the each taxon to use. `0` is equivalent to `FALSE`. Negative numbers are equivalent to `TRUE`.
(`function` of length 1) If `taxon_weight` option is used and `supertaxa` is `TRUE`, the weights for each taxon in an observation's classification are supplied to `collapse_func` to get the observation weight. This function should take numeric vector and return a single number.
Additional options are passed to [filter_obs()].
DEPRECIATED. use "data" instead.
Other taxmap manipulation functions:
arrange_obs(),
arrange_taxa(),
filter_obs(),
filter_taxa(),
mutate_obs(),
sample_frac_taxa(),
sample_n_obs(),
sample_n_taxa(),
select_obs(),
transmute_obs()
# Sample half of the rows fram a table
sample_frac_obs(ex_taxmap, "info", 0.5)
# Sample multiple datasets at once
sample_frac_obs(ex_taxmap, c("info", "phylopic_ids", "foods"), 0.5)
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