# Blog

## How does Douglas peucker algorithm work? ## What is the role of the parameter epsilon in Ramer Douglas peucker algorithm?

Ramer-Douglas-Peucker Algorithm, also known as Douglas–Peucker algorithm and iterative end-point fit algorithm, is a cartographic/line generalization algorithm. It basically reduces the number of points in a curve/line without losing the shape of the curve/line, based on some tolerance parameter 'epsilon' (ε).Sep 19, 2021

## What is line simplification?

Sometimes our lines and polygons are way too complicated for the purpose. To make things easier, we decide to simplify my polygon. ... Simplification means that we want to express the same geometry, using fewer points, but trying to preserve the original shape as much as we can.Apr 27, 2020

## Why line simplification is required?

Amazingly, simplification often allows the elimination of 95% or more points while retaining sufficient detail for visualization. For example, the GeoJSON file used to draw the continental United States above can be reduced from 531KB to 27KB with only minor visual changes.Jun 1, 2012

## How is line simplification carried out in GIS?

Simplification removes extraneous bends and small intrusions and extrusions from a line without destroying its essential shape. The Simplify Line tool uses one of two simplification algorithms, called point remove and bend simplify.  ### What is Ramer Douglas Peucker line simplification?

• Ramer-Douglas-Peucker line simplification. The Ramer–Douglas–Peucker algorithm is a line simplification algorithm for reducing the number of points used to define its shape.

### How to simplify a piecewise linear curve using Douglas Peucker algorithm?

• Simplifying a piecewise linear curve with the Douglas–Peucker algorithm. The starting curve is an ordered set of points or lines and the distance dimension ε > 0. The algorithm recursively divides the line. Initially it is given all the points between the first and last point. It automatically marks the first and last point to be kept.

### What is the purpose of the similarity algorithm?

• The purpose of the algorithm is, given a curve composed of line segments (which is also called a Polyline in some contexts), to find a similar curve with fewer points. The algorithm defines 'dissimilar' based on the maximum distance between the original curve and the simplified curve (i.e., the Hausdorff distance between the curves).

### How to make a point detection algorithm non-parametric?

• Like most line fitting / polygonal approximation / dominant point detection methods, it can be made non-parametric by using the error bound due to digitization / quantization as a termination condition. The algorithm is used for the processing of vector graphics and cartographic generalization.