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4.3.1.2. Geoprocessing
Each of functionality in geoprocessing group is described in the following text:
4.3.1.2.1. Vector-based Grid Data Preparation
The transformation from vector to grid format is always suffered by the imprecision of grid representation. In very simple form, the accuracy value of flat
surface polygon shown in the Figure 30 transformation into the vector-based grid form the vector grid is given by the ratio of the sum of all grid areas
132783443.00 m
2
and polygon area 132795516.19 m
2
, which gave value 0.99991 or almost 100. The accuracy is reasonably large because the edge of
polygon is represented by partial grids, as shown in the Figure 45. The partial grid was possibly produced since the grid is actually a polygon as well vector
type data.
Figure 45. The Partial Grid Created in the Edge of Concerned Polygon Vector-based grid data model certainly has some advantage and
disadvantage. Vector-based grid is actually vector data which composed almost by rectangular shape and it has attribute that contains value represent spatial
properties. Hence, it inherits the advantage and disadvantage of both vector and raster data type. This issue is briefly provided in the Table 8 below.
70 Table 8. The Advantage and Disadvantage of Vector-based Data Model
ADVANTAGE • Mathematical modeling is easy because all entities have a regular shape.
• Retrieval, updating, and generalization of graphics and attributes are
possible. • Conducting topological operation is possible.
DISADVANTAGE • Large data volumes grid size-dependent
• The speed of processing is slower than raster data model.
The result of embedding process could be evaluated through examining the attribute of output file. The output file should have several fields containing value
from chosen spatial analysis computation. Figure below shows the attribute of output file containing expected fields and values.
Figure 46. Attribute Table of the Output File from Embedding Process
4.3.1.2.2. Buffering Point
This utility gave expected result to both buffer types rectangular and circular, means that it can be used for further processing, i.e. spatial properties
examination. However, there is a different in processing time of spatial properties examination between both types, which circular type took much time longer than
the other one such as neighbor analysis. This is happened because of every circular polygon of the output has many vertices as illustrated by Figure 47.
71 Figure 47. The Vertices of Circular Polygon Produced from Buffering Utility
4.3.1.2.3. Dissolve
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