#!F-adobe-helvetica-medium-r-normal--18*
#!N 
#!CSlateBlue #!N  #!Rqimd Importing Data #!N #!EC #!N #!N Importing data 
into Data Explorer is the first step in creating a visualization 
of that data. Data Explorer supports the importation of a number 
of data formats: General Array Importer, Data Explorer native, CDF, netCDF, 
and HDF (see  #!Limd,dxall618 h Importing Data: File Formats  #!EL  in IBM Visualization Data Explorer User's Guide). 
The General Array Importer is discussed here not only because it 
can import a variety of data types but because its supporting 
interface makes it useful to the broadest range of users. This 
interface consists of the Data Prompter, for describing the data to 
be imported, and the Data Browser, for viewing the data. #!N 
#!N This chapter deals with the importation of data in the 
following sections: #!N #!I0 #!N  #!F-adobe-times-medium-r-normal--18*   #!N #!N #!I30 #!N o 
 #!Lgai,dxall110 h General Array Importer  #!EL  #!N #!I30 #!N o  #!Lgaiexs,dxall114 h Importing Data: Header File Examples  #!EL  #!N #!I30 #!N o  #!Lsydfgi,dxall139 h Header File Syntax: Keyword Statements  #!EL  
#!N #!I30 #!N o  #!Lprompt,dxall157 h Data Prompter  #!EL  #!N #!I30 #!N o  #!Lbrowse,dxall169 h Data Prompter Browser  #!EL  #!N 
#!I0 #!N #!EF #!N #!CIndianRed #!N #!N #!N  #!F-adobe-times-bold-r-normal--18*   An Important 
Note on Fields #!N #!N Importing data into Data Explorer requires 
some knowledge of the Data Explorer data model and at least 
a working knowledge of a  #!F-adobe-times-medium-i-normal--18*   field #!EF . #!N #!N 
 #!F-adobe-times-medium-i-normal--18*   Fields #!EF are the fundamental objects in the Data Explorer 
data model. A field represents a mapping from some  #!F-adobe-times-medium-i-normal--18*   domain 
#!EF to some  #!F-adobe-times-medium-i-normal--18*   data space #!EF . The domain of 
the mapping is specified by a set of  #!F-adobe-times-medium-i-normal--18*   positions #!EF 
and (generally) a set of  #!F-adobe-times-medium-i-normal--18*   connections #!EF that allow interpolation 
of data values for points between positions. Positions represent what can 
be thought of as (and often really are) locations in space; 
the data are the values associated with the space of the 
positions. The mapping at all points in a domain (not just 
those specified by the given positions) is represented implicitly by specifying 
that the data are dependent on (located at) the sample points 
or on the connections between points. #!N #!N This simple abstraction 
is sufficient for representing a wide range of information. For example, 
you can describe 3-dimensional volumetric data whose domain is the region 
specified by positions and whose data space is the set of 
values associated with those positions. The domain of a 2-dimensional image 
on a monitor screen is a set of pixel locations, and 
the data space consists of the pixel color. For 2-dimensional surfaces 
imbedded in 3-dimensional space (e.g., traditional graphical models) the domain may 
be a set of positions on the surface, and the data 
space a set of data values on that surface. #!N #!N 
In Data Explorer the positions and data are said to be 
 #!F-adobe-times-medium-i-normal--18*   components #!EF of a field, and every field must contain 
at least a "positions" component and a "data" component. Fields may 
also contain other components (e.g., "connections"). Thus a Data Explorer field 
consists of data and the additional components needed to describe that 
data so that Data Explorer can process it. #!N #!N  #!F-adobe-times-bold-r-normal--18*   
(cont.) #!EF #!N #!N #!EC #!CIndianRed #!N #!N #!N  #!F-adobe-times-bold-r-normal--18*   An 
Important Note on Fields (cont.) #!N #!N 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 data dependency). The syntax of defining fields in 
the General Array format is described in  #!Lsydfgi,dxall139 h Header File Syntax: Keyword Statements  #!EL  . The various 
components are described in IBM Visualization Data Explorer User's Guide. #!N 
#!N #!EC #!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next Topic #!EF #!N #!N 
 #!Lgai,dxall110 h General Array Importer  #!EL  #!N  #!F-adobe-times-medium-i-normal--18*   #!N 
