In a previous article, GIS and Decision Support (3): A tool for creating fuzzy
criteria with ArcMap , we have seen a tool for transforming numeric
attribute into a soft attribute (fuzzy number).
In this article we will discuss and put at your disposal the last one that
makes it possible to create a soft attribute (fuzzy number) starting from a
text attribute containing a classification of the entities.
The tool is composed of a command, “Text criterion”,
that makes it possible to transform a textual criterion into a fuzzy number.
The original criterion is a text field of a layer of a feature class. The
contents of this field include classified values that will be transformed
into another field, numeric, but with values within the range 0-1. This
transformation takes place to match the values of the origin field with a
degree of satisfaction of the field, criterion: 1 corresponds to a total
satisfaction, 0 to a total dissatisfaction, the other values being partial
satisfactions.
Using the command “Text criterion”
Once the command is installed (see below), the
button
displays the following interface:
Command
interface Text criterion
Warning: The command works on shapefiles and Geodatabases
files. It does not work on personal Geodatabases.
The window is divided into two panels:
- The first one allows to select
the attribute to be transformed in a fuzzy number,
The second allows to define the transformation
values.
Choosing the attribute to be transformed
The “Data Layer “window displays
the different layers loaded in the ArcMap window.
By selecting a layer in this window, you get the list of text attributes
available in that layer.
The “Non-Text Fields ” window displays the other attributes
present in the attribute table of the selected layer but are not text fields. The
command automatically filters the fields of type OBJECTID, GRIDCODE,
shape_area, etc.
You can also check the box “Fields with value 0-1 “. In
this case, only numeric fields with values in the table between 0 and 1 will
be displayed.
Warning! To this end, the command calculates the statistics of each
numerical attribute. This process takes a lot of time, depending on the number
of numeric fields and especially the number of records. Try not to use this
option too often.
The metadata button allows displaying the metadata (criterion,
date, etc.) of a fuzzy attribute present in the attribute table. To use it, select
the field in the list of non-text fields, and click the metadata button.
Once you have selected an attribute in the Available Attributes list,
you will see the list of different values present in the attribute table.
Display
of the classification present in the attribute table
The command also gives you a name for the new attribute to be created. You
can modify it, knowing that it will be limited to 10 characters if it concerns
the processing of a shapefile.
Choice of transformation values
The definition of transformation takes place in
four steps:
Configuration
of the criterion transformation table
The first concerns the definition of the number of satisfaction classes
to use (1).
You can choose 3, 5 or 7 classes. Depending on the choice, the number of
available classes (3) changes automatically.
If you select 3 classes the command will propose the following transformations:
• Excellent will be transformed into value = 1
• Average will be transformed into value = 0.5
• Excluded will be transformed into value = 0
If you select 5 classes the command adds the options:
• Good which will be transformed into value = 0.75
• Poor that will be transformed into value = 0.25
If you select 7 classes the command will propose the following
transformations:
• Excellent which will be transformed into value = 1
• Very good which will be transformed into value = 0.83
• Good that will be transformed into value = 0.67
• Medium that will be transformed into value = 0.5
• Poor that will be transformed into value = 0.33
• Very bad which will be transformed into value = 0.17
• Excluded which will be transformed into value = 0
Once you have chosen the number of classes,
select the values in the left window (2), tick the satisfaction index you
want to assign to the selection (3), then click on the >>
button to pass the values to the right window
The number between 0 and 6 indicates the choice assigned to each value
- 0 -> Excluded
- 1 -> Very bad
- 2 -> Poor
- 3 -> Medium
- 4 -> Good
- 5 -> Very good
- 6 -> Excellent
You can cancel one or more choices by selecting the value in the right
window and clicking the button << . Values are
returned to the left window.
Processing aids: metadata
The button
displays a window with the description of the soft criteria contained in the data layers.
The following window shows an metadata example for a soft criterion:
The metadata is stored in a separate file (.fzy), managed by the
command.
The management of these files is automatic. For example, the elimination of
metadata corresponding to a soft criterion if it is manually deleted from the
table of the feature class.
However, if you move layers to different directories or geodatabases, you will
need to move the .fzy file manually.
A text criterion will be indicated by a 999 type. Currently, the transformation
table is not stored in the metadata.
Available languages
A drop-down list allows you to select the language to use.
The available languages are:
• French (default)
• English
• Spanish
• Vietnamese
Even if the command is supposed to switch from one language to another
without any problem, depending on the version of Windows used, it is safer to
close and reopen the command after selecting another language from the
drop-down menu.
Versions of ArcGis
Commands can be used with ArcGis versions between 9.2 and 10.3. Downloading the command (Version 10.3.0.5)
Manual use of fuzzy criteria text
Command installation
The tools are provided as a .dll file.
To install it you have to go through the ArcMap menu Customize ->
Customize mode.
The customization window opens:
On the Commands tab, click the Add from File button. Select the fuzzy_textV92_103ML.dll file that you have previously copied to a permanent directory of your local disk WITH the Text.mdb file delivered at the same time. If you have already installed the previous commands, replace the existing file with this one. This file contains the different versions of the languages used. It is not very elegant, but it allows the command to work without special adaptation with Xp, Vista, W7 and W8.
Click OK. The following message should appear to indicate that the installation was successful
Click OK. In the available Commands window you will be automatically positioned on the NASCA commands category and you will see the available tool: Text Criteria.
To be able to use it, click-drag on the command icon and drop it into an open ArcMap toolbar.
