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#!N 
#!CDarkGreen #!N  #!Rmbmdf (2) Create a module description file #!N 
#!EC #!N #!N Data Explorer's graphical user interface and executive access 
the module description file to determine the names of the modules 
and their inputs and outputs. #!N Note: This type of file 
is commonly referred to as an "mdf" file (because of its 
file extension) and is created automatically from user input to the 
Module Builder, as described in  #!Lmblder,dxall1003 h Module Builder  #!EL  . However, for very simple 
modules like the one in this example, it is usually easier 
and quicker to create the file with a text editor. #!N 
#!N #!N Parameter names are a part of the module interface 
that can be seen by the user. In the graphical user 
interface, parameter names appear in the configuration dialog box and also 
serve as default names for interactors. In the scripting language, module 
parameters can be specified by name. #!N #!N A new module 
cannot have the name of an existing Data Explorer module (see 
IBM Visualization Data Explorer User's Reference for a complete list). You 
should also be aware of the following requirements: #!N #!I0 #!N 
 #!F-adobe-times-medium-r-normal--18*   #!N #!N #!I30 #!N o A Data Explorer module name 
must be a single alphanumeric string and its first character must 
be a letter. (Standard Data Explorer module names capitalize the first 
character of each "word" in a name, as in Attribute and 
AutoAxes. You may observe this convention or not, as you wish, 
for the modules you create.) #!N #!I30 #!N o The module 
must be assigned to a tool category--in a  #!F-adobe-times-bold-r-normal--18*   CATEGORY #!EF 
statement in the module description file. The category can be any 
of those listed in the Category palette of the VPE window 
or a new one that you create by naming it in 
the statement. #!N #!I0 #!N #!EF #!N #!N #!N In the 
following example, the mdf file consists of five statements: #!CForestGreen #!N 
#!N  #!F-adobe-courier-bold-r-normal--18*   #!N #!N MODULE Hello #!N CATEGORY Greetings #!N DESCRIPTION 
Prefixes "hello" to the input string #!N INPUT value; string; "world"; 
input string #!N OUTPUT greeting; string; prefixed string #!N #!EF #!N 
#!N #!EC #!N #!I0 #!N #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   MODULE 
#!EF #!EF #!I50 #!N Specifies the module name as Hello. #!N 
#!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   CATEGORY #!EF #!EF #!I50 #!N Assigns the 
module to a new, user-specified category (Greetings). #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*   
 #!F-adobe-times-bold-r-normal--18*   DESCRIPTION #!EF #!EF #!I50 #!N Describes Hello's purpose: to affix 
"hello" to the input string. #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   INPUT 
#!EF #!EF #!I50 #!N Assigns the name  #!F-adobe-times-bold-r-normal--18*   value #!EF to 
the input parameter; specifies its parameter type as  #!F-adobe-times-bold-r-normal--18*   string #!EF 
; specifies its default value as "world"; and describes it as 
an input string. #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   OUTPUT #!EF #!EF 
#!I50 #!N Assigns the name  #!F-adobe-times-bold-r-normal--18*   greeting #!EF to the output 
parameter; specifies its parameter type as  #!F-adobe-times-bold-r-normal--18*   string #!EF ; and 
describes it as a prefixed string. #!I0 #!N #!N #!N #!N 
For details, see  #!Lmdfsec,dxall1046 h Module Description Files  #!EL  . #!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next Topic 
#!EF #!N #!N  #!Lall993,dxall994 h (3) Write the module  #!EL  #!N  #!F-adobe-times-medium-i-normal--18*   #!N 
