This chapter describes how to use the graphical user interface provided with Data Explorer. This interface enables you to create and control the visualization of data. An image is created by applying data, as input, to a visual program. The visual program is a sequence of interconnected functions acting on one or more inputs and producing one or more outputs. Typically, input is user data and output is a realization of that data in the form of an image.
Data Explorer consists of the following windows:
You can use the Startup window to access other windows in Data Explorer.
Visual Program Editor
You can use the Visual Program Editor (VPE) to create and alter visual programs and macros.
You can use Control Panel windows to set and control the input parameters of visual program tools.
You can use the Image window to view an image created by Data Explorer.
You can use the Colormap Editor to map colors and opacity to specified data.
You can use the Sequencer to advance through a data series or to step through a changing sequence of input parameters.
You can use the Message window to access error and working information about your execution.
You can use the Help window to access online documentation.
A graphical user interface that simplifies the import of data.
A graphical user interface that simplifies the process of adding modules to Data Explorer.
To run Data Explorer using a workstation, you must have:
You can start Data Explorer in any of several modes. In all cases, you must first do the following:
If you are going to create, modify, and execute visual programs, start Data Explorer initially in the Visual Program Editor and connect to the executive (server) by typing:
dx -edit [program]where program (which is optional) names an existing visual program.
If you plan to execute a previously created visual program, start Data Explorer initially in the Image window and connect to the executive (server) by typing:
dx -image programor
dx -menubar programwhere program is the name of an existing visual program.
You may want to start the user interface without connecting to the executive. For example, you may want to work on a visual program or macro, but may not plan to execute it until some later time. In that case, you can start Data Explorer with the following command:
dx -edit -uionlyOnce the user interface is started, you can connect to the executive portion of Data Explorer by following the procedures described in 9.3 , "Connecting to the Server".
All of the command line options for Data Explorer are described in C.2 , "Command Line Options".
There are several environment variables that you may find useful to customize Data Explorer. These can be set in your login profile, or set as required.
The DXMACROS environment variable is a list of the directories in which Data Explorer will look for macros. If you do not specify DXMACROS, you will need to load macros individually, using the process described in 7.2 , "Creating and Using Macros". The directories are searched in the order in which they are specified in the environment variable. If multiple macros with the same name are encountered, the first macro found is used.
An example of the statement setting the DXMACROS environment variable (in the C shell environment) is the following:
setenv DXMACROS /usr/mydirectory/projectAmacros:/usr/mydirectory/projectBmacroswhere /usr/mydirectory/projectAmacros and /usr/mydirectory/projectBmacros are two directories in which macros will be sought. Multiple directories can be listed, with directory names separated by a colon.
The DXDATA environment variable specifies a list of directories in which Data Explorer will search for data files. If the data you wish to import are in one of the directories specified in the DXDATA environment variable, then you do not need to specify the complete path name to the data in the Configuration dialog box for the Import tool. You can simply specify the file name, and the Import module will look in the specified directories for the data file. The directories are searched in the order in which they are listed in the environment variable; and the first occurrence of the data file is used.
An example of a statement that sets the DXDATA environment variable (in the C shell environment) is the following:
setenv DXDATA /usr/mydirectory/mydata:/usr/group/groupdatawhere /usr/mydirectory/mydata and /usr/group/groupdata are two directories that contain data files. Multiple directories can be listed, with directory names separated by a colon.
The DXHOST environment variable is the initial machine name of the workstation on which to run the executive. If DXHOST is not specified, then a default of "localhost" is used. See 9.3 , "Connecting to the Server" for more information on how to connect to the server. The host name should be the name that results when you issue the uname -n shell command.
The rest of the environment variables and start-up options are discussed in Appendix C. "Environment Variables and Command Line Options".