Create a measure

A measure is a governed calculation inside a semantic_layer(). Its function body is ordinary R; its arguments schema tells the model what inputs it can supply.

Usage

measure(name, description, fn, arguments = list(), title = NULL)

Arguments

name

Measure name.

description

What the measure computes.

fn

Function that computes the measure.

arguments

A named list of ellmer::type_string() and friends describing the arguments the model supplies. Arguments of fn not listed here are hidden from the model: they receive a matching data source's connection or keep their defaults. See semantic_layer().

title

Human-readable measure title to show in user interfaces. If NULL, a title is derived from name.

Value

A measure object.

See also

semantic_layer() to collect measures into a layer.