#!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
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