join: Equi-join

In tera-insights/gtBase: R Interface for the Grokit System

Description

Joins two tables by columns on the basis of equality of attributes.

Usage

Join(x, xAtts, y, yAtts)

Arguments

x	an object of class "data" to be used on the left hand side of the join. It is more efficient for this to be the larger of the two tables.
xAtts	the attributes of x to be used in the equality condition. Specified in the format of inputs.
y	an object of class "data" to be used on the right hand side of the join.
yAtts	the attributes of y to be used in the equality condition. Specified in the format of inputs.

Details

The specified attributes are matched in pair. For example, given xAtts = c(att1, att2) and yAtts = c(att3, att4), the condition of the join is att1 == att3 && att2 == att4. This format necessiatates that xAtts and yAtts have the same length.

Value

The result of the join, i.e. the subset of the cross product that satisfies the given equality conditions.

AUTO

Neither xAtts nor yAtts is allowed to be AUTO due to the context - this would lead to duplication of entire rows.

Author(s)

Jon Claus at Tera Insights LLC

See Also

Filter

Examples

nation <- Read(nation100g)
region <- Read(region100g)
j1 <- Join(nation, n_regionkey, region, r_regionkey)

tera-insights/gtBase documentation built on May 31, 2019, 8:35 a.m.