C o m m o n A c c e s s
t o G e o g r a p h i c a l l y
R e f e r e n c e d D a t a
USERMANUAL
C o m m o n G I S U s e r M a n u a l
E u r o p e a n C o m m i s s i o n , D G I N F S O , E S P R I T P r o j e c t N o . 2 8 9 8 3
( P r o j e c t D e l i v e r a b l e D 4 . 7 . 2 ; J R C - I S I S )
J u n e 2 0 0 1
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A W ALKT H R O U GH I NT O CO M MO NGIS
U S E R M A N U A L
THE COMMONGIS USER MANUAL AT A GLANCE
.
PART 1 - OVERVIEW
6 AIMS AND ACHIEVEMENTS,
COMMONGIS SOLUTIONS,
USER SCENARIOS AND DEMONSTRATORS,
THE USERS’S PERSPECTIVE,
FEATURE LIST AND H/W S/W REQUIREMENTS,
THE COMMONGIS CONSORTIUM
PART 2 - A WALKTHROUGH USING THE FOREST FIRES APPLICATION
13 STEP 1 — COMPARING ATTRIBUTES
Basic display and zooming, removing outliers and comparing regions
21 STEP 2 — SHOWING TRENDS
Using the display wizard to get parallel bar charts and visually compare maps
27 STEP 3 — SEEKING RELATIONSHIPS
Using the calculate wizard and scatter plots to seek relationships
33 STEP 4 — MORE RELATIONSHIPS
Using the scatter plot and the parallel coordinate plot to analyse values graphically
U S E R M A N U A L
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How to use this manual This short manual is intended both to be read “off-the-computer”,
as an introduction to CommonGIS, and to be used in front of a
computer as a first tutorial to CommonGIS.
Manual plan The User manual is divided into two parts:
Part 1 is an introduction and presentation of CommonGIS aims,
solutions and requirements.
Part 2 is organised as a tutorial and aims at taking the user through
a quick guided tour involving some of the main features available.
It is divided into steps and each step is in turn divided into sections.
Although each section is organised as a one (rarely two) page selfstanding
unit of information, we suggest, whenever possible, to
follow all the pages in a step without interruptions.
This manual is intended to demonstrate only the usage and user
interface of CommonGIS software, and not to evaluate the
exemplary data sets used here, which are only functional to
introduce the program use.
Special notation Scattered through all the guided tour steps there are special parts
marked by shadowed boxes: these are ADDITIONAL INFO
BOXES.
HOW TO USE THIS MANUAL
ADDITIONAL INFO BOX —…
These boxes contain notes on current actions being described or
hints on alternative actions to take in case some options are not
available or suitable to the user.
They also host quick hints on more functions available or suggestions
for user self exploration of program features.
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U S E R M A N U A L
PART 1 - OVERVIEW
AIMS AND ACHIEVEMENTS·························································6
COMMONGIS SOLUTIONS···························································7
USER SCENARIOS AND DEMONSTRATORS··························8
THE USER’S PERSPECTIVE························································9
FEATURES: FUNCTIONS AND I/O CAPABILITIES················10
HARDWARE AND SOFTWARE REQUIREMENTS·················11
THE COMMONGIS CONSORTIUM············································12
U S E R M A N U A L
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AIMSANDACHIEVEMENTS
CommonGIS aims to disseminate and make available spatially-referenced
data to a broad cross-section of the public. With this initiative, we hope
to have succeeded in our purpose: GIS for everyone, from everywhere.
"GIS for everyone" because the target audience of CommonGIS is a wide
variety of people who need to use geo-data for work or study but are
not specialists in GIS and data presentation design. Users include local
authorities, teachers and marketing professionals, just to name a few.
CommonGIS doesn’t exclude, however, highly-qualified professionals in
various fields who aren’t proficient in operating GIS and don’t have time
to learn. The goal is to make GIS data available to all that cannot afford
expensive GIS software and equipment and/or do not posses the
knowledge required to efficiently use it.
"GIS from everywhere" because CommonGIS applications can be accessed
through the Internet using a standard Java-enabled Internet browser.
This allows casual users to access and utilise geo-referenced data from
any networked computer.
In general terms, CommonGIS makes geo-data readily accessible and
usable for everyone, from everywhere, by providing a web-based
Geographical Information System (GIS) with specific functions to
automatically generate thematic maps.
CommonGIS makes it possible to explore and analyse geo-data easily
and clearly with interactive and direct manipulation tools.
This translates into software that:
• provides access to remotely located geo-data through the Internet
• automatically generates thematic maps that correctly and effectively
present map-based visualisations of geo-data sets selected by the
user;
• displays the generated maps on the user's side;
• supports exploratory geo-data analysis by enabling map modification
with the use of direct manipulation techniques;
• provides all necessary user interactivity while requiring no special
software from the user's side except a standard (Java -enabled) Web
browser.
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U S E R M A N U A L
COMMONGISSOLUTIONS
The solution is based on Java technology, so the interactive interface can
be downloaded on-demand independently of the location, hardware and
operating system of the user.
In order to analyse spatially referenced data, it is necessary to present
them on a map, which should be properly designed with respect to data
characteristics and relationships among data items.
Since each presentation method imposes certain limitations on data it can
be applied with, a system
that automates the
preparatory stage offers
considerable help to the
analyst. It releases the
user from working on
map design and therefore
from the necessity to
learn the principles of
graphical presentation.
The user is therefore able
to devote more time and
attention to data analysis.
A significant new feature is the knowledge based task assistant, which can
be accessed by users, advising them on the best visualization options for
their applications. Such support is
particularly important for novice
users. The fact that this
parameterized knowledge base
automatically instantiates itself to
the notions of a new domain
represents a very effective user
adaptation strategy. The techniques
developed can also be ported to
other application areas.
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APPLICATIONSCENARIOS
Two representative application scenarios using the CommonGIS
product were selected and developed in the project:
• The “Buy a House Scenario” - selection among spatial locations or
areas (e.g. selection of a house to buy, selection of a vacation site,
etc.)
• The “Education Scenario” - exploration of statistical data referring
to administrative areas (e.g. exploration of demographic data
about European states).
Each of these applications could
easily be extended to cover
other similar applications.
A number of demonstrators
have been prepared and
presented. These illustrate the
applicability of the CommonGIS
technologies to a large number
of different application areas.
E.g. Forest fires (image),
Earthquake catalogues, and
Naturdetektive - which has
been used by school children
across Germany.
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U S E R M A N U A L
From the users’ perspective, CommonGIS supports this work scenario:
• By way of a standard WWW browser the user has access to a catalog
of available geo-data, indicating for each data set its topic (population,
housing, industry, environmental pollution etc.), territory (Germany,
Europe, …), and territorial units (cities, districts, countries, …) the data
refer to. The user selects a data set to work with. In response, an index
of attributes contained in the selected geo-data set will be shown.
• The user selects one or more of these attributes. In response, the user
immediately receives a map that visualizes data for the selected
attributes. The map is supplied with a legend. Map and legend are
generated completely automatically, without any involvement of the
user. The system takes care about the correct presentation and
visualization of the data in the maps, i.e., visualization techniques are
properly chosen depending on characteristics of the data fields being
represented and relationships among them, in compliance with
principles of graphic and cartographic presentation. This prevents
misinterpretation of data and supports adequate and effective data
analysis, and on this basis, facilitates proper problem solving and decision
making.
• Remaining within the WWW browser, the user can view the map with
the aid of all necessary facilities: zooming, panning, layer selection etc.
The user can also access the exact data values associated with
geographical objects: the values are shown when the mouse cursor
approaches an object in the map.
• The map on the user’s screen is not a mere reproduction of a paper
map. It is dynamic, i.e. able to change its properties in real time in
response to certain user actions (direct manipulation). The direct
manipulation tools offered to the user are designed in a way that
promotes the revelation of interesting and important data features and
spatial patterns that could remain unnoticed in a static map.
• The system also supports database querying and manual construction of
derived fields by means of arithmetical or logical operations over
existing fields. The results of these operations can be automatically
visualized and analysed with the help of the direct manipulation
techniques.
THEUSER’SPERSPECTIVE
1
2
3
4
5
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FEATURES
Map visualizations
(“mapping”)
Choropleth maps for one numeric attribute
Choropleth maps for one qualitative attribute
Choropleth maps for cross classification
Choropleth maps for other classifications
Multiple choropleth maps
Diagrams
Bar charts
Pie charts
Stacked bars
Triangles for two attributes
Utility bars
Utility pies
Graph visualizations
(“charting”)
Dot plot
Scatter plot
S-plot matrix
Parallel coordinate plots
Tukey’s box plots
Histograms
Data transformations
(“calculation”)
Classification of one attribute
Classification of two attributes (cross classification)
Classification by dominant attribute
Classification by n-dimensional attribute similarity
Ideal point evaluation
Ordering of values
Average/Median/Quartiles/Variance
Calculation of arbitrary formula
Filter objects according to specified attribute values
Features - Functions
Zoom out (to maximal extent)
Zoom out (by factor)
Zoom in (with rectangle)
Zoom in (by factor)
Undo last zoom
Shift the map
Select mouse mode (zoom, pan, select or explore)
Basic map functions
Layers
Change the order of layers
Change layer properties
Change the size and color of symbols
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U S E R M A N U A L
REQUIREMENTS
Open new window with current map
Minimize all
Restore all
Close all
Bring an open window to the front
Windowing
Features - Data Input and Output
User support
General system help
Task support guide: support based on characteristics
of data and intended goal of the user
General information about system and application
Show advanced menu items
Show menu items for application building
Hardware and Software Requirements
The CommonGIS system is implemented in Java™ language, and can run as
applet in the web browser; therefore it will run if the Internet browser supports
Java™ applets. A recent version of Netscape or MS IExplorer will be enough.
Some browsers have an option to disable Java™. If you disabled it, you can't run
the applet, too.
A PC computer, with at least 16 MB of RAM, can run the system using
Netscape 4.x or Internet Explorer 4.0 or higher.
Data Input
• Load attribute data from: DBF, Oracle
Spatial, CSV (Excel), TXT (delimited text),
ODBC/JDBC, clipboard.
• Load geographical data from: OVL (GMD
Descartes), SHP (ESRI Shapefile), JPEG, GIF,
FLT (grid data), WKB, Simple Features and
GML (OpenGIS)
• Open a pre-defined map description MWI
Data Output
• Display data records on mouse-over
• Edit options for display of data records
• Print map
• Save map as image
• Save application
• Select objects by mouse-click
• Find objects according to specified attribute
values
• Display table with all objects
U S E R M A N U A L
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THECOMMONGISCONSORTIUM
The roots of CommonGIS software lie in the rich experience of the
partners in computer graphics, GIS, knowledge-based systems and data
visualisation.
The CommonGIS Consortium is composed of seven public and private
companies from five countries of the European Union. It is very marketoriented
and took into consideration the user needs and requirements
during the development process.
CNIG (Portugal) is an institution responsible for running the
Portuguese network of geo-referenced data. They provided geo-data
sets and specifically interacted with the end users in the validation
process.
Dialogis (Germany), an independent GMD spin-off, commercialised a
version of IRIS/Descartes system, an advanced prototype for the
automatic generation of thematic maps. It contributed to further
professional development and commercial exploitation of CommonGIS.
GMD (Germany) develops the IRIS/Descartes system and has been
responsible for the overall management of the project, together with
JRC.
IGD (Germany) has built another prototype for thematic mapping
(Vizard). They supplied direct experience in studying the user
acceptance and adequacy of different map presentations.
JRC (Italy) contributed knowledge about developing distributed
applications, particularly for the use of geographical and statistical
information. It also managed the dissemination and standardisation
activities.
PGS (Netherlands) built a Java-based GIS (LAVA), which has been
integrated with IRIS/Descartes and appropriately extended for the
specific needs of this project. PGS and Dialogis have agreed on a
mutual utilisation of results (see the License information).
The European GIS association GISIG, subcontractor of JRC, put to
use its excellent dissemination channels to promote the results of the
project and to help in the standardisation effort.
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A W ALKT H R O U GH I NT O CO M MO NGIS
U S E R M A N U A L
THE FOREST FIRES APPLICATION ········································14
SHOWING THE NUMBER OF FIRES·········································16
ENHANCING THE MAP DISPLAY··············································18
THE TASK SUPPORT GUIDE·····················································20
PART 2 - AN EXEMPLARY
WALKTHROUGH
STEP 1 :
Comparing Attributes
U S E R M A N U A L
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A W ALKT HR O U G H I NT O CO M MO N GIS
1. Let us start up the Forest Fires CommonGIS application by
accessing it through a JAVA-enabled WWW browser at
http://commongis.jrc.it/forestfires/ .
2. After the JAVA application has been downloaded (this requires a
variable time, depending on the Internet access speed available), the
main CommonGIS window shows up.
THE FOREST FIRES APPLICATION
1.COMPARINGATTRIBUTES
The LAYER PANEL allows to include (+) or
exclude (-) specific map layers by clicking on
them. In this case the two layers are a Raster Map
representing ground heights and a NUTS3 region
layer.
Double clicking onto the NUTS3 layer in this
pane allows to control the line and/or fill colours.
THE FOREST FIRES DATA
The Forest Fires application uses data about fires in 23 regions of Spain,
collected by the JRC during the years 1991-1993.
The attributes available for each region and for each year are:
• the total number of events (NUMEV91, 92, 93)
• the total area burned (ARBURN91, 92, 93)
• the MIN, MAX and AVERAGE delay between the first alarm and the
start of extinguishing intervention (MIN-MAX-AVDELAY91, 92 , 93)
• the MIN, MAX and AVERAGE duration of the fire (MIN-MAXAVDUR91,
92, 93)
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A W ALKT H R O U GH I NT O CO M MO NGIS
U S E R M A N U A L
3. With CommonGIS it is possible to start exploring the data without
wasting any time learning complicated systems: the user interface is
essential but powerful.
1.COMPARINGATTRIBUTES
Most of the buttons visible have familiar
appearance: simple map operations (like zoom in,
zoom out, pan, select feature) can be done using
these buttons.
Useful tool tips pop-up when the mouse “touch”
buttons and controls to clarify the meaning of any
element of the interface.
U S E R M A N U A L
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Which is the region that had
most fires in year 1991?
1.COMPARINGATTRIBUTES
1. To answer to this question it is possible to build a map that could
show with degree of darkness the attribute “Total events in 1991”.
2. Click on display and start the display wizard.
SHOWING THE NUMBER OF FIRES
The RIGHT-ARROW button adds to the display list
the attribute previously selected in the left pane with
the mouse. The LEFT-ARROW removes attributes.
The UP/DOWN-ARROW buttons allows to change
the order of the attributes selected for display.
3. Select the attribute
"Number of events in
1991" (NUMEV91)
and click "OK".
4. The second stage of the wizard asks
what kind of representation to use.
Click on "degree of darkness"
and then on "OK".
5. The map which shows up on the
CommonGIS window displays the
regions with higher number of fires in
1991 with darker colours.
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U S E R M A N U A L
1.COMPARINGATTRIBUTES
6. While it is evident which region was mostly affected by fires, there
are little differences in the presentation, between the regions that
have lower numbers of fires: we will see how CommonGIS can help.
By pointing the mouse cursor over any region of
the map a tool tip will pop-up showing the exact
number of fires in 1991 (NUMEV91), together
with the region name and ID.
Regions for which there is no data
available are displayed in grey.
CHANGING THE RANKING COLOURS
Clicking on the “rainbow” rectangular icon in the bottom of the right
pane a Colour selection
dialogue opens. You can
change the positive and
negative colours to be used. Note that since in
the NUMEV91 attribute no negative values are
allowed, the negative colour is never used.
U S E R M A N U A L
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1.COMPARINGATTRIBUTES
ENHANCING THE MAP DISPLAY
How can we discriminate better among
regions with lower numbers of fires ?
2. In the right pane, i.e. the
legend/manipulation
pane, drag the upper
triangular delimiter to
remove the so called
“outliers” (the values
that are much higher or
lower than the mean).
1. There are small differences in the display colours of the regions that
have lower numbers of fires. It could help the visualization to put
emphasis on the lower values.
3. The new max
display value is
reported in the
Max numerical
field.
The Min display
value can be set
similarly.
Regions excluded are also displayed in grey
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A W ALKT H R O U GH I NT O CO M MO NGIS
U S E R M A N U A L
1.COMPARINGATTRIBUTES
ORANGE:
more fire
events than
the
reference
region
How does one region
compare to another ?
BLUE:
fewer fire
events than
the
reference
region
4. Clicking on a
region, sets the
value associated
as a reference
point thus
enabling visual
exploration
capabilities.
Reference region for comparison
THE DOT-PLOT AND THE MAP
The dot-plot diagram is composed by two main grey plotbars,
plus the left colour scale bar we have already seen in
action. These bars are also active and linked to the map. By
hovering the mouse on the bars the closest dots-values are
highlighted, their values and region identifier are displayed
and the corresponding region in the map gets highlighted.
The right plot-bar always shows the full set of values for the
attribute being displayed, while the mid bar shows only the
values within the upper and lower limits set, repositioning the
dots to cover the full bar range.
The upper and lower values-to-be displayed in the map can
be set either by dragging the triangular handles or by typing
numerical values in the “Min” and “Max” fields. Also the
reference value for comparison (see the map above) can be
set numerically with the “Compare to:” field.
U S E R M A N U A L
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A W ALKT HR O U G H I NT O CO M MO N GIS
Activating the Task Support Guide “wizard” (menu Help -> Task
Support Guide … option) gives another way in the use of CommonGIS.
The systems guides the user through a number of selections and offers
instructions (always in green background), task choices and, given a
certain task, suggests actions and possible tools useful to that aim.
Choosing tools (instruments) will ultimately start the display/analysis tools
using the proper attributes.
Help tool tips pop-up by passing the mouse
cursor over the tool list proposed.
THE TASK SUPPORT GUIDE
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U S E R M A N U A L
TRENDS IN THE QUANTITY OF FIRES ···································22
KEEPING MAPS ············································································24
TRENDS IN NUMBER OF FIRES AND AREA BURNED········25
STEP 2 :
Showing Trends
U S E R M A N U A L
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4. From the representation methods available choose
“Parallel bars”, useful to detect trends and
compare values. Click the OK button.
Please note that only the display options which
could apply to the attribute selection are enabled.
1. Since in the dataset there are also the data for years 1992 and 1993,
it can be interesting to see the trends in the quantity of fires for each
region and find out when the highest number of fires for each region
occurred. One appropriate method to discover these things is to use
a parallel bar visualization.
2. From the Display menu start the Display Wizard again.
TRENDS IN THE QUANTITY OF FIRES
2.SHOWINGTRENDS
3. Add the attributes
“Number of events” for
years 1992 and 1993
(NUMEV92 and
NUMEV93) and click the
OK button.
5. In the “Check comparability of attributes”
dialogue showing up click YES to confirm.
Note that because of this confirmation,
unless you tick the “do not memorize …”
option, CommonGIS will learn (memorise)
that these attributes are comparable and will
not ask you for any further confirmation for
the same attribute choice.
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U S E R M A N U A L
2.SHOWINGTRENDS
6. In the map window,
it is easy to detect
the region that has a
steady increase in
the number of fires
during the period of
time 91-93.
Also that region has
the highest number
of events, thus
making the parallel
bar display of other
regions poorly
representative
7. By dragging the upper arrow in the manipulation window to exclude
a few outlying values, the visualization can be adjusted to put more
emphasis on lower values, which are all grouped in a smaller interval.
Now we can see that
the other regions do
not show dramatic
increase in the
number of events:
their values seem to
be pretty stable.
The values removed from the
current display are marked with
arrows.
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The “saved” map and manipulation pane are actively
connected to the map in the main application window
KEEPING MAPS
This saved map is:
• Still active and configurable: the manipulate and legend pane
are fully functional as well as the toolbar. It is therefore
possible to zoom, pan, remove outliers, change colours, etc.,
exactly as in the main application window.
• Connected to the main application window: hovering the
mouse over points in the manipulation pane or in the map in
the “saved” window, causes the corresponding map area in the
main window to be highlighted/selected.
The toolbar and the legend/manipulation pane
are still fully functional in the “saved” window
2.SHOWINGTRENDS
1. To keep the current map, for later comparison, select the Display
menu and the “Keep the map” item.
2. A second window opens with the saved map .
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U S E R M A N U A L
TRENDS IN NO. OF FIRES AND AREA BURNED
Is the trend in area burned per region
similar to the trend in the quantity of fires ?
2.SHOWINGTRENDS
1. We first need to display the trend in area burned per region: from
the Display menu start the Display Wizard again
2. Let us first clear the previously selected
attribute list by clicking on the CLEAR
button.
3. Then select
ARBURN91 (area
burned in 1991) in the
left pane and use the
RIGHT-ARROW to
add it to the attributes
to visualise.
4. Repeat the previous
selection also for
ARBURN92 and
ARBURN93.
5. In the “Select a graph to be built” dialogue choose
“Parallel bars” and click on the OK button.
6. In the “Check comparability of
attributes” dialogue showing up click
YES to confirm.
U S E R M A N U A L
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7. Visually exploring the “Area Burned” trend map, which is still
actively connected with the “Number of Fires” trend map saved
previously we can see that the two trends do not seem to coincide in
every
region.
2.SHOWINGTRENDS
Some regions also
exhibit opposite
trends in the area
burned and in the
number of fires.
8. There are other useful tools to search for relationships between the
area burned and the number of fires.
In the next step we will consider and compare total quantities, over
the 3 years spanned in the database, for the same attributes.
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U S E R M A N U A L
CALCULATING THE TOTAL AREA BURNED ························28
CALCULATING THE TOTAL NO. FIRES ·································30
BUILDING A SCATTER PLOT GRAPH·····································31
STEP 3 :
Seeking Relationships
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Is the total area burned per region high
where the total quantity of fires is also high ?
1. To address this question we must first compute the aggregated data.
Within CommonGIS it is possible to calculate the both the total area
burned during the period 1991-1993 and the total quantity of fires in
the same years span.
2. Start the Calculate Wizard by selecting menu and item Calculate ->
Calculate….
3. Since in the “Select attribute(s)
for calculation” dialogue we
already have the area burned
attributes for years 1991-1993,
we keep this selection and
hence start by computing the
sum of the area burned.
Click the OK
button to confirm.
4. Choose Sum of columns as a calculation
method in the next dialogue and click OK.
CALCULATING THE TOTAL AREA BURNED
3.SEEKINGRELATIONSHIPS
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U S E R M A N U A L
5. In the subsequent “check inclusion of all attributes in
one” select Sum of ARBURN91, ARBURN92,
ARBURN93 and click OK to confirm.
6. Then, in the “check inclusion of attributes”,
we press the YES button to confirm that the
3 attributes chosen represent non overlapping
parts of the new attribute being created.
7. Finally we give a meaningful
name to the attribute being
calculated, like Total area
burned 1991-1993 and click
OK.
8. CommonGIS displays
the darkness map of
the total area burned
in each region within
the period 1991-1993.
3.SEEKINGRELATIONSHIPS
U S E R M A N U A L
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2. At the end of the procedure
CommonGIS displays the darkness
map of the total quantity of fires in
each region within the period
1991-1993.
CALCULATING THE TOTAL NUMBER OF FIRES
1. To calculate the total quantity of fires during the period 1991-1993
we proceed exactly as in the previous section (remember to clear
the attribute selection list when calculating the new aggregated
attribute).
3.SEEKINGRELATIONSHIPS
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U S E R M A N U A L
4. Select the chart
Scatter Plot
and click
the OK
button.
5. The scatter plot graph shows that
some sort of linear correlation
may exist between the number of
fires and the total area burned,
since the dots representing the
(no. fires, area burned) attribute
couples are approximately
distributed along a straight line .
.
1. After calculating the total number of events, it is possible to get a
scatter plot graph. Start the Display Wizard …
2. Push the CLEAR LIST
button to get rid of the
previous selection.
3. Then select the calculated
attributes:
Total area burned 1991-
1993 and Total number of
fires 1991-1993
and click the OK button to
confirm.
3.SEEKINGRELATIONSHIPS
BUILDING A SCATTER PLOT GRAPH
An outlier, a value that is
completely out of the mean range,
is easily visible
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3.SEEKINGRELATIONSHIPS
THE SCATTER PLOT GRAPH
By dragging the vertical &
horizontal triangular sliders the
plot can be focused on the
central cloud, excluding outliers
The plot is actively
connected to the main
window map.
By pointing to a point
in the graph the
corresponding region
in the map is outlined
and the associated
attribute values are
displayed.
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PLOTTING AVERAGE DELAY AND DURATION ···················34
USING THE PARALLEL COORDINATES PLOT ····················37
STEP 4 :
More Relationships
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Is there any relation between the number of
fires and the delay or the duration of fires?
1. To address this question it is necessary to calculate the average
duration of fires and the average delay between the alarm and the
beginning of the intervention. We will use averages across all the
time span covered by the database, i.e. 1991, 1992 and 1993
2. Start the Calculate Wizard by selecting menu and item Calculate ->
Calculate….
3. Clear any possible previous
selection by pushing the
CLEAR LIST button, then
select and add attributes
“average delay between alarm
and intervention” (AVDELAY)
for the years 91, 92 and 93.
Click the OK button to
confirm.
4.MORERELATIONSHIPS
4. Choose Average among columns as a calculation
method in the next dialogue and click OK.
5. Finally we give a meaningful
name to the attribute being
calculated, like Average
delay of intervention 1991-
1993 and click OK.
3.SEEKINGRELATIONSHIPS
PLOTTING AVERAGE DELAY AND DURATION
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4.MORERELATIONSHIPS
6. Repeat the whole procedure using the “average duration of
fires” (AVDUR) for the three years 91, 92 and 93.
7. We name the new attribute
Average duration of fires 1991-1993.
3.SEEKINGRELATIONSHIPS
8. We start the Display Wizard, select the
calculated attributes Average delay of
intervention 1991-1993 and Average
duration of fires 1991-1993 and click
the OK button.
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4.MORERELATIONSHIPS
9. Finally we select Scatter Plot and click the OK button.
10.The scatter plot confirms that there is no strong correlation
between the duration of the fire and the delay in the
intervention.
11.This could be more evident if we compare this scatter plot
with the previous one (the one displaying number of fires
versus area burned).
In fact CommonGIS keeps the previous plot (s), unless
CommonGIS provides controls
to switch or distribute the
display between the plots
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4.MORERELATIONSHIPS
1. Start the Display Wizard …
2. Then select the following attributes:
Total area burned 1991-1993,
Total number of fires 1991-1993,
Average delay of intervention
1991-1993, Average duration of
fires 1991-1993 and click the OK
button to confirm.
3. Select the Parallel coordinates plot chart and click
the OK button.
4. The new window shows a parallel bar plot.
USING THE PARALLEL COORDINATES PLOT
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4.MORERELATIONSHIPS
5. The parallel bar plot graph is useful for studying relationships
between variables.
It is possible to reorder variables by dragging the attribute names in
the right window pane: mostly non-intersecting lines indicate positive
correlation, whilst mostly-intersecting lines indicate negative
correlation.
AFTER RE-ORDERING THE ATTRIBUTES ...
D e s i g n e d b y D i c i a n n o v e & D o c - A - W a r e