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)
In this article, we will understand about Vector Data in detail.
- 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.
- Each point is well-defined by a particular x, y coordinate.
- There may be several points in a vector point file.
- Sampling locations
- The site of individual trees
- The position of survey plots.
- 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.
- A polygon contains of three or more vertices that are linked and wrapped.
- 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.
- 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.
Pros and Cons of Vector Data
- The geometry that one covers data about what the dataset maker said was vital.
- The geometry structures grip facts in themselves.
- For example why select point over polygon?
- Each geometry feature may carry many attributes in place of just one.
- For example, a database of cities may have qualities for name, country, and population.
- Data storage can be very well-organized likened to rasters
- Possible loss of part likened to raster.
- Potential prejudice in datasets. What didn’t become recorded?
- Designs linking many vector layers essential to do math on the geometry along with the attributes, therefore can be slow related to raster math.