---
title: 4.2.3 Compactness
description: "![](https://isovists.org/wp-content/uploads/2024/02/Compactness-1280x254.jpg) *Compactness* (Cv) expresses the shape property (relative to a circle) of all space visible from a location. In an isovist field, compactness identifies the regions of plan in which an observer’s spatial experience is contiguously consistent. Such regions identify…"
url: "https://isovists.org/user-guide/4-2-3-compactness/"
updated: "2024-02-14"
category: 4 How the Calculations Work / 4.2 Isovist Measure Definitions
---

# 4.2.3 Compactness

![](https://isovists.org/wp-content/uploads/2024/02/Compactness-1280x254.jpg)

*Compactness* (Cv) expresses the shape property (relative to a circle) of all space visible from a location. In an isovist field, compactness identifies the regions of plan in which an observer’s spatial experience is contiguously consistent. Such regions identify and correlate to meaningful instances of [Peponis’ S- and E-partitions](http://www.umich.edu/~igri/publications/OnTheDescriptionOfShape.pdf) (Peponis, 1997); identifying opportunities for the emergence of new surfaces in the visual field as a result of movement.

To determine compactness, the Isovist_App calculates a form of the [isoperimetric quotient](http://mathworld.wolfram.com/IsoperimetricQuotient.html) of the isovist for every point ‘V’ in plan. The outcome is a relative value between 0 and 1.

In notation form the calculation for Compactness is expressed as: 

![](http://isovists.org/wp-content/uploads/2020/07/Eq_Compactness.jpg)

*Where ‘Av’ is the area value; and ‘Pv’ the perimeter value.*