# Numerical

The Numerical strategy visualizes (*x*, *y*) coordinates.

## Intent

It mainly aims to answer:

*What is the relationship between two variables?**How does a variation in one variable affect the other?*

## Presentation metaphor

Data, together with *Numerical with frequency*.

## Context meta-model

The context meta-model of Numerical contains a single class, `Target`

, with two numeric attributes `x`

and `y`

.

## Visualisation variants

There are three available visualizations:

**Line Graph**and**Area Chart**, ideal for data ordered by the X axis; and**Scatter Plot**, for independent x and y values.

## Properties

`title`

: string [1..1]. Title of the visualisation.`X_label`

: string [0..1]. Label for the x axis.`Y_label`

: string [0..1]. Label for the y axis.

## Motivating example

The strategy can be used to understand the "size" of meta-model concepts in a single chart. In particular, it associates the X and Y coordinates to the number of attributes and relationships of a concept, respectively.