//dooloust.net/4/5074590 https://propellerads.com/publishers/?ref_id=mrlj Introduction of Vector Data |Vector Data |

# Introduction of Vector Data

### Introduction

There are three changed means to think about vectors. A vector as;

• An array of numbers (a computer science vision)
• An arrow with a direction and magnitude (a physics outlook)
• An object that follows addition and scaling (a mathematical view)

### Description

• Vector data provides particular features on the Earth’s outward.
• It allocate attributes to those features.
• Vectors are composed of separate geometric locations (x, y values).
• These are recognized as vertices that describe the shape of the spatial object.
• The group of the vertices describes the type of vector.
• That we are working with as point line or polygon. ### Points

• Each point is well-defined by a particular x, y coordinate.
• There may be several points in a vector point file.

Examples

• Sampling locations
• The site of individual trees
• The position of survey plots.

### Lines

• Lines are composed of various points that are related. At least two points are needed.
• For example, a road and a stream can be denoted by a line.
• This line is composed of a sequences of segments.
• Each curve in the road and a stream signifies a vertex that has defined x, y location.

### Polygons

• A polygon contains of three or more vertices that are linked and wrapped.

Examples

• The shapes of survey plot boundaries
• Outline of lakes
• Sketch of oceans
• States or countries

### Vector data in GIS environment

• Maximum GIS applications collection vector features into layers.
• Features in a layer have the similar geometry type such that they would all be points.
• They have the equal types of attributes such that information about what classes a tree is for a trees layer.
• For instance if we have logged the positions of all the footpaths in our school, they would generally be kept on the computer hard disk.
• Those will be shown in the GIS as a single layer.
• This is suitable as it permits us to hide or show all of the features for that layer in our GIS application with a single mouse click.

### Cutting out vector data

• The GIS application will permit us to make and adapt the geometry data in a layer.
• This process is named digitising.
• The GIS application will merely permit us to make new polygons in that layer if a layer comprises polygons.
• Likewise, the application would only permit us to do it if the altered shape is correct and if we want to change the figure of a feature.
• For instance it won’t let us to edit a line in such a way that it has only one vertex.
• As all lines must have at least two vertices.
• Making and editing vector data is a vital function of a GIS.
• Ever since it is one of the core means in which we can make personal data for things we are interested in.

Example

• We are observing pollution in a river.
• We could use the GIS to digitise all vents for storm water drains.
• We could similarly digitise the river itself as a polyline feature.
• Lastly we could take readings of pH levels beside the course of the river.
• Digitise the spaces where we made these readings as a point layer.
• There is many free vector data that we can obtain and use on top of making our own data.
• We can get vector data for instance that seems on the 1:80 00 map sheets from the Chief Directorate: Surveys and Mapping.