as-vector: Convert Variables to local R objects

Description Usage Arguments Details Value See Also

Description

Crunch Variables reside on the server, allowing you to work with datasets that are too big to bring into memory on your machine. Many functions, such as max, mean, and crtabs(), translate your commands into API queries and return only the result. But, not every operation you'll want to perform has been implemented on the Crunch servers. If you need to do something beyond what is currently supported, you can bring a variable's data into R with as.vector(ds$var) and work with it like any other R vector.

Usage

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## S4 method for signature 'CrunchVariable'
as.vector(x, mode = "any")

## S4 method for signature 'CrunchExpr'
as.vector(x, mode = "any")

Arguments

x

a CrunchVariable

mode

for Categorical variables, one of either "factor" (default, which returns the values as factor); "numeric" (which returns the numeric values); or "id" (which returns the category ids). If "id", values corresponding to missing categories will return as the underlying integer codes; i.e., the R representation will not have any NA elements. Otherwise, missing categories will all be returned NA. For non-Categorical variables, the mode argument is ignored.

Details

as.vector transfers data from Crunch to a local R session. Note: as.vector returns the vector in the row order of the dataset. If filters are set that specify an order that is different from the row order of the dataset, the results will ignore that order. If you need the vector ordered in that way, use syntax like as.vector(ds$var)[c(10, 5, 2)] instead.

Value

an R vector of the type corresponding to the Variable. E.g. CategoricalVariable yields type factor by default, NumericVariable yields numeric, etc.

See Also

as.data.frame for another interface for (lazily) fetching data from the server as needed; exportDataset() for pulling all of the data from a dataset.


crunch documentation built on April 6, 2021, 1:05 a.m.