Given a numeric column within a Spark DataFrame, compute
approximate quantiles (to some relative error).

sdf_quantile(x, column, probabilities = c(0, 0.25, 0.5, 0.75, 1),
relative.error = 1e-05)

## Arguments

- x
- An object coercable to a Spark DataFrame (typically, a
`tbl_spark`

).
- column
- The column for which quantiles should be computed.
- probabilities
- A numeric vector of probabilities, for
which quantiles should be computed.
- relative.error
- The relative error -- lower values imply more
precision in the computed quantiles.