#!F-adobe-helvetica-medium-r-normal--18*
#!N 
#!CSeaGreen #!N  #!Rfields Fields #!N #!EC #!N #!N 
Given the sets of numbers, "positions," "connections," and "data," we can 
define a  #!F-adobe-times-medium-i-normal--18*   Field #!EF , as it is called in 
Data Explorer. The positions identify locations in space, the (optional) connections 
define logical continuities (interpolation paths) between positions, and the data are 
the values measured either at each position or within each connection 
element. Data Explorer calls each of these sets of numbers (positions, 
connections, data) a Field  #!F-adobe-times-medium-i-normal--18*   component #!EF . Components are represented 
as arrays of numbers with some auxiliary information specifying  #!F-adobe-times-medium-i-normal--18*   attributes 
#!EF (e.g., type of dependency). In addition, there are many other 
types of Field components. The Field is the basic unit of 
information in Data Explorer, so it is important to understand how 
to express your data in these terms. #!N #!N A Field 
can only have one "positions" and one "connections" component. A Field 
can have only one component actually named "data," but you may 
assign names of your choosing to additional components representing other data 
sets that are also mapped to the same grid. So you 
can name a "data" component "temperature" and another "wind velocity," or 
you can just use the default name "data" if you only 
have one "data" component. #!N #!N The ".dx" file format provides 
the most flexibility for describing data sets to Data Explorer. But 
many researchers produce fairly straightforward arrays of numbers mapped onto regular 
or deformed regular grids. If your data are already written out 
in such a form, you may not need to convert your 
data files into the native ".dx" file format. Instead, Data Explorer's 
General Array Importer can read your data directly, given a small 
"header" file that you create to tell the General Array Importer 
the name of your data file and its dimensions (see  #!Lqimd,dxall109 h Importing Data  #!EL  
in IBM Visualization Data Explorer QuickStart Guide). #!N #!N This shorthand 
description is enough for Data Explorer to convert your data structure 
into a Field when it reads your raw data file. You 
will still find it valuable to understand the components of a 
Field, because once you begin using the Data Explorer visual programming 
language, you will have direct access to these components. Much of 
the power and flexibility of the visual programming language is derived 
from our ability to access and manipulate Field components in a 
variety of ways. #!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next Topic #!EF #!N 
#!N  #!Lall195,dxall196 h Visual Programming: The Basics  #!EL  #!N  #!F-adobe-times-medium-i-normal--18*   #!N 
