Statistics Questions

Describe the difference between using Statistics and using Summarize functions on a field.

Requirement

Minimum 200 words each

Individual word files with Individual references

APA Format

(You could potentially get 30 points for your answers on this Discussion Question,If the answer is substantial, complete and correct. The answers have to be original, interesting and up-to-the-point. Your personal thoughts, critical thinking and analytical approach will be valued the most!)

References

Kang-Tsung Chang (2016) Introduction to Geographic Information Systems, 9th edition, NY: McGraw-Hill ISBN19: 978-1-259-92964-9

Additional Reading Materials:

• Wilpen Gorr, Kristen Kurland (2017) GIS Tutorial 1 for ArcGIS PRO, ESRI Press,
• Michael Law, Amy Collins (2018) Getting to Know ArcGIS Desktop, 5th edition for ArcGIS 10.6, ESRI Press

GEOSPATIAL INTELLIGENCE
& GIS
LECTURE 5.
GIS DATA FORMAT and
EXCHANGE
Professor, Dr. Sergei Andronikov
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TIN: Triangulated Irregular Network
TIN is a list of points with
coordinates.
You connect ANY 3 points
to represent an area of
UNIFORM topography.
Way to handle field data
with the vector data
structure.
Common in some GISs
and most AM/FM
packages.
Vectors and 3D
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Volumes (surfaces) are structured with the TIN model,
including edge or triangle topology.
The network is a set of triangles. TINs use an optimal
Delaunay triangulation of a set of irregularly distributed
points.
2 sorts of TIN can be built: 1. With a file containing the
info about the arcs that connect points.
2. Containing all the data about ONE triangle.
TINs are popular in CAD and surveying packages.
As a way of storing topography or land elevation data
for visualization and engineering.
Vector Vs. Raster
ADVANTAGES
VECTOR
Good Representation of entity
data models. Map analog.
Compact data structure
Topology can be described
explicitly. Good for network.
Coordinate transformation and
rubber sheeting is easy.
Accurate graphic
representation at any scale.
Retrieval, updating, and
generalization of graphics and
attributes are possible.
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RASTER
Simple Data Structures;
Location-specific manipulation
of attribute data is easy;
Many kinds of spatial analysis,
and filtering may be used;
Mathematical modeling is easy
(all spatial entities have a
simple, regular shape);
The technology is quite cheap;
Many forms of data are
available.
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
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Vector Vs. Raster
DISADVANTAGES
VECTOR
Complex Data structures;

Combining several polygons and

overlay analysis is difficult & requires
computer power;
Display and plotting may be timeconsuming and expensive;

Spatial analysis is impossible without
extra data (polygons are considered 
to be internally homogeneous);
Simulation modeling of spatial
interactions is more difficult, because
each spatial entity has a different

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
RASTER
Large data volumes;
Using large grid cells to
reduce data volumes
reduces spatial resolution
result in loss of info;
Crude raster maps are
inelegant;
Coordinate
transformations are
difficult and time
consuming.
General public doesn’t

Vector Vs. Raster
RESULT
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
Only a few years ago:
Vector systems were seen as being truer to
conventional cartographic images, and were
essential for high quality map-making and
topographic accuracy.
Raster systems were seen as being suitable
only for overlay analysis.
Today:
Many GIS support both vector and raster
structures.
FORMATS
Most GIS systems can import different
data formats, or use utility programs to
convert them.
 Data formats can be industry standard,
commonly accepted or standard.

Vector Data Formats
Vector formats are either page definition
languages or preserve ground coordinates.
 Page languages are: HPGL (designed for use
with plotters & printers), PostScript (Developed
by Adobe Corporation. Uses ASII files), and
Autocad DXF (ASCII file in a binary mode).
 True vector GIS data formats are DLG (Digital
Line Graph. USGS) and TIGER (used for
census), which has topology.

The TIGER data structure
Landmark
Addresses
on block
Map 3
157 6
2
156
Zero cells
159
158
Nodes 13,17,18,19,
21,22,23,156,157,
158,159
(x,y) values
8
First St.
3
5
86
11
88
21 7
Avenue A
18
90
91
13
13
12
Zero cell
Two cell
22
Second St.
10
85
89 9
14
Third St.
17 15
18
1,2,3,4,5,6,7,8,
9,10,11,12,13,14,
15,16,17,18
Addresses
17
16
19
One cell
One cells
23
Avenue D
4
Lake Drive
Avenue C
87
Avenue B
1
Files
Two cells
Lake, Blocks 86,
87, 88, 89, 90,
91
Raster Data Formats
Most raster formats are digital image
formats.
 Most GISs accept: TIF (Tagged
Interchange Format),
 GIF (Graphic Interchange Format);
 JPEG or encapsulated PostScript, which
are not georeferenced.
 DEMs of the USGS are true raster data
formats. Widespread acceptance

EXCHANGE
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Most GISs use many formats and one data
structure.
If a GIS supports many data structures, changing
structures becomes the user’s responsibility.
Changing vector to raster is easy; raster to vector
is hard.
Data also are often exchanged or transferred
between different GIS packages and computer
systems.
The history of GIS data exchange is chaotic and
has been wasteful.
Vector to raster exchange errors
GIS Data Exchange
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Data exchange by translation (export and import) can lead
to significant errors in attributes and in geometry.
In the United States, the SDTS (Spatial Data Transfer
Standards) was evolved to facilitate data transfer.
SDTS became a federal standard (FIPS 173) in 1992.
SDTS contains a terminology, a set of references, a list of
features, a transfer mechanism, and an accuracy standard.
Both DLG and TIGER data are available in SDTS format.
Other standards efforts are DIGEST, DX-90, the TriService Spatial Data Standards, and many other
international standards.
Efficient data exchange is important for the future of GIS.
Transfer Standards