JGView Usage Documentation
Usage Documentation | Installation | Usage Examples

Links to Additional Information

CD-ROM technical support page for the latest updates

About the JGView Development Team

Introduction | Screen Layout | Selecting Data | Criteria | Viewing | Exporting
Extending JGView | Troubleshooting

1.0 Introduction

1.1 General Overview

JGView, a platform-independent computer program written in Java, provides a graphical user interface for subselection, viewing, and export of data collected for U.S. JGOFS. JGView enables the user to browse through the catalog of U.S. JGOFS data, select any set of parameters from a data file, define subselection criteria for those parameters, view the data in tabular form, and export the subselected data in a variety of file formats. These file formats include, Ocean Data View (ODV) Generic and General Formats, MATLAB format, and Tab/Comma Delimited formats.

1.2 Look and Feel

JGView comprises three window panes. The upper-left pane holds the catalog of the U.S. JGOFS dataset within a tree-structure used for browsing. Once a data file selection has been made, the window pane to the upper-right asks for parameter criteria for targeting the desired data within that data file. After the criteria have been established, this window pane will display the selected data in tabular form. Finally, the pane below both the catalog and the data is the documentation pane. The documentation pane displays metadata for the presently selected data file.

1.3 Ease of Use

JGView was designed to provide quick and easy access to a data collection and enable subselection of data to suit a user's needs. The U.S. JGOFS Process Study data has been cataloged into a tree-like browsing structure allowing users to locate data of interest. After selecting a data file, JGView supports subselection of the data within that file based on selection criteria associated with each parameter. Once selection criteria have been set, data can be viewed in the data window pane or simply exported to a file in one of the various file formats. As an alternative to browsing through the tree, JGView has a search function that can search the catalog for a user-specified data parameter and return a list of hypertext links to data entities in which the parameter was found.

1.4 JGView Data Files

The data files used by JGView are all in tab-separated value format (.tsv files). The data files can be found in the /data directory on the CD-ROM. JGView mirrors the exact file structure of this data directory to use as the tree catalog. JGView uses support files to help gather information such as parameter descriptions, units, and metadata about the selected data file. These support files have the same basename as the data file, but with different file extensions. The .ndx files are used to display metadata and .htm files are parsed for the parameter descriptions and units. For the Merged Product files, the parameter information comes from the param_master.dct (U.S. JGOFS master parameter dictionary) file at the top of the /data directory. Every time a data file is selected from within JGView, the metadata for that data file is displayed in the lower documentation window pane. The parameter descriptions and units are used in naming the catalog entities and helping with the subset, view, and export functions.

If you are having trouble with any of the JGView functions, select the 'Start Over' option from the File menu.

1.5 Running JGView

The U.S. JGOFS dataset is extremely large. Running JGView from the CD-ROM preserves space-efficiency. However, to gain optimal performance, we recommend copying the CD-ROM to your hard disk. JGView will always try to find the data directory relative to its location. The relative path defaults to ../../data. If the /data directory is not found at the default location, JGView prompts for new locations for the /data, /docs and /images directories. This feature permits users to arrange their file system in a manner that suits their capabilities while ensuring that JGView will continue to function properly. See section 7.1 Moving JGView off the CD-ROM.

  See Installation instructions document to install the JRE and run JGView.

1.6 Getting Started

When JGView starts up, it loads the Java Virtual Machine. This can take up to one minute depending on the operating environment. JGView displays a U.S. JGOFS splash screen image while it loads all files in the data directory. After the splash screen disappears, you may begin subsetting data. Navigate through the data catalog tree to a data file of interest. Expand the data file so that its parameters are displayed in the data catalog tree. Highlight the parameters that you would like to subset from the data file and press the 'Subset' button. In the right pane, define the selection criteria for these parameters and press either the 'View Data' button to see the selected data or the 'Export' button to save the data to a file in any of the supported file formats. Information about the currently selected data file is displayed below in the Documentation window pane. Press the blue info icon or the 'Info' button from the toolbar to view detailed documentation about the data file in your system's default browser. Use the toolbar 'Search' button to search the data catalog tree. The search generates a link list in the documentation window which can be used to locate data files within the data catalog tree.

  Refer to JGView Examples document for examples on how to use JGView.

2.0 JGView Screen Layout

The JGView window consists of a main menu bar and toolbar at the top, the data catalog window pane on the left, the data subset and viewing window pane on the right, and the documentation window pane at the bottom. Window pane sizes can be changed by dragging the bars that separate them.

2.1 Main Menu

Start Over:
  clear all views and selections and reset the catalog tree back to its original display
Refresh Tree:
  reread the file structure of the /data directory and rebuild the data catalog tree including any new files
  exit JGView 

Copy Documentation Window:
  copy contents of the lower documentation window pane to the clipboard
Copy Search Results:
  copy search results from the lower documentation window pane to the clipboard
Default Browser:
  if the operating system is Linux, this option allows the user to set the default browser for JGView to use. The choices are either Netscape or Mozilla.

About JGView:
  returns generic information about JGView
JGView Documentation:
  opens this file in default browser window

2.2 Toolbar

Info: When active, clicking this button opens default browser and displays HTML documentation for current data selection. This button is only active when that HTML file exists for the current selection.
Search: Provides a text search of the entire U.S. JGOFS catalog on every parameter and its description. Results are displayed in JGView's lower documentation window pane.
Subset: Displays the current selection criteria in the data view window pane (right pane).
View Data: All data matching the selection criteria are listed in the data view window (right pane).
Export: All data matching the selection criteria are exported to a file in user-specified format.

2.3 Data Catalog Tree

The window pane on the left of the application is the data catalog tree, and it is a tree-structured representation of the file system holding the U.S. JGOFS data files. All of the data is stored in the /data directory on the CD-ROM. Each directory on the file system, is represented by a folder icon. Each data file within these folders, is indicated by an INFO icon . Each parameter within the data file, is indicated by a leaf icon . The icon appearances vary with operating system environment and may change over time with software updates.

The data is categorized at the first level of the tree according to the basin in which the data was collected. The four U.S. JGOFS basin studies were North Atlantic, Equatorial Pacific, Arabian Sea and Southern Ocean. At the next level the data has been grouped according to 'data type' or oceanographic discipline. This level comprises labels such as Biological, Chemical, Metadata, Sediment Core, etc. All categories are designated by the folder icon .

Data files within the 'data type' categories are identified by an information icon . Clicking on an information icon opens the corresponding HTML information file in a browser window (same as the INFO button on the Toolbar). Each data file's parameters are listed below its description. All parameters are designated by the file icon, on Windows and on the other operating systems.

2.4 Data View Pane

The window pane on the right of the application display is the Data View pane. This pane has two purposes 1) to display the selection criteria for selected parameters when the 'Subset' button has been clicked, and 2) to display selected data when the 'View Data' button has been clicked.

The selection criteria are displayed in tabular form with each selected parameter occupying one row. The 'Reset Criteria' button, atop the table, resets all selection criteria back to their default settings.

The display of selected data is also presented in tabular form with each parameter occupying one column. These columns can be rearranged by clicking on the column header and dragging to the desired location within the table.

2.5 Documentation Pane

The documentation window pane occupies the lower portion of the JGView display screen. It is used to 1) display data file information whenever a data file has been selected, and 2) display search results.

2.6 Documentation and Data View Borders

Whenever the documentation pane or data view pane is displaying data file information, its border will display the file system path to that data file. For example, the biology file N_uptake_atlantisII from the North Atlantic basin would be expressed in the border as its true file path North_Atlantic/Biological/Productivity/N-uptake_atlantisII.

3.0 Selecting Data

Data can be selected for any number of parameters within one data file. When expanding the data file to view its parameters, all parameters are selected by default, except for data files in the Merged Product category which do not select all parameters by default. To modify a data selection click on the parameters listed beneath the data description to either add/remove it to/from the selection based on its previous state. To finish the selection, click the 'Subset' button from the Toolbar to display the selected parametersÂ’ selection criteria. At any time, you may add or remove parameters from the selection by clicking them in the catalog tree and then clicking 'Subset'. Previously established selection criteria will be unaffected by the addition or removal of parameters.

Selections cannot be made between two or more data files.
If an invalid selection is requested, JGView will indicate the remedial action.

  Refer to JGView Examples document for an example of parameter selection.

3.1 Using the Data Catalog Tree

To subset data, highlight any combination of parameters so long as those parameters are all in the same data file. The parameters of a data file are always the leaf icons of the tree (they cannot be expanded). When a data file becomes highlighted (selected), an arrow will appear to it's left. This signifies that it is now the active file for subsetting. If a data file has been highlighted and not expanded, pressing 'Subset' will include all of the data file's parameters in the next step, defining the extraction criteria. Expanding the data file will show that all parameters are highlighted meaning they are selected to be subsetted. Clicking a highlighted parameter will deselect it, vice versa. By clicking on parameters, the user either selects or deselects that parameter depending on its previous state.

Collapsing a data file will remove all selections from within that data file. This includes collapsing any path to that data file. For instance, if N_uptake_atlantisII in the North_Atlantic/Chemical/Chem path is the current data file, collapsing any of the North_Atlantic, Chemical or Chem entities will remove all selections made for the N_updake_atlantisII file. No warning of this removal will occur unless you have previously clicked the 'Subset' button. If 'Subset' was previously clicked, the user is given the option of continuing with the new operation and losing the current work or to return to the current work and restore JGView to its previous state. If a subset had not been taking place, JGView assumes that you never intended to work on the selected data since you have collapsed it. This same warning behavior occurs if a selection is made outside the current data file. The warning gives you the option to continue or cancel the new selection and return to the current subset.

Parameters cannot be selected across more than one file. If you are working on a current subset and click within that same data file to either add or remove parameters, this is allowed. If you click on another data file, you will be notified of this and have the choice to either continue and lose your current subset or return back to your current subset.

3.1.1 Merged Products

Merged products exist as a grouping under each basin and these data files operate slightly different from what is described above. For a given merged product data file, the parameters below it are also grouped. Like the other data files, highlighting the data file entity in the tree includes all parameters into the subset. Also, by highlighting a grouping under the data file entity in the tree, the subset will include the parameters within that grouping. For example, by highlighting the 'Chemical' grouping under a merged product data file, the subsequent subset will only contain the parameters under the Chemical grouping. The difference between these data files and the other data files with respect to how they operate in the tree, is that as you expand the groupings, the parameters are not highlighted. So, to include all of the parameters for a given group, regardless of whether that grouping is closed or expanded, so long as that grouping entity in the tree is highlighted, all of its parameters will be in the selected subset. To select individual parameters from a grouping, click the desired parameters. By clicking parameters, they become highlighted (selected). Only the highlighted parameters will be included so long as the grouping itself is not highlighted. This functionality was implemented so that by not highlighting all parameters, when expanding a grouping, a user would not have to click the undesired parameters to remove them from the selection. This way, a user can include all parameters if desired by highlighting the grouping entity, or select only the desired parameters by clicking those parameters.

  Refer to JGView Examples document for an example of Merged Product parameter selection.

Note: if event, year, sta, lat, lon, depth exist as parameters under the Sampling Attributes group of any merged product data file, they are automatically included in your subset. You can remove them from your selection once you get to defining the criteria by simply unchecking the box in the Subset column. Deselecting these parameters from the data catalog tree does not remove them from the subset.

Since these data files have their parameters grouped, collapsing the groups after you have made selections under that group does not remove them from the selection. This is allowed to save viewing room when working in these data files. Therefore, you may make selection within one grouping, collapse it, and make selections within another grouping without losing any of your previous selections.

  Refer to JGView Examples document for an example of Merged Product parameter selection.

3.2 Clearing Selections

Any selection can be cleared by selecting 'File -> Start Over' from the Main Menu.

3.3 Searching for Data

JGView can search through the entire U.S. JGOFS dataset for any instance of a string of characters found within a parameter's name or description. The Search capability is only available while you are not working within a dataset either defining criteria or viewing data. To perform a Search, click the 'Search' button from the toolbar. Type a character string in the text entry box. Click the [Go] button and JGView will search the entire data catalog for this text string.

Search results are displayed in the documentation window pane at the bottom of the application. Each result is a clickable link that will navigate you directly to that instance of data in the catalog tree. From there you may either click on a new result or begin to make parameter selections within the catalog tree.

Once you do start to make selections within the tree, your search results will be replaced with the documentation for the data file from which you are currently working. So, at the top of the results, there is a clickable link that allows you to print these results. If you would like to copy the results or a section of the search results to your clipboard, highlight the section of interest using the mouse or other mechanism, and from the Main Menu, select 'Edit -> Copy Search Results'. The search function remembers the last value you searched for, so if you would like to run the search again, click 'Search' and the last character string will be placed in the text field for searching.

  Refer to JGView Examples document for examples of searching from JGView.

4.0 Defining Criteria

After you have made a selection of parameters and pressed the 'Subset' button, the data window pane provides the option of specifying certain selection criteria that would reduce the number of results returned. After defining the desired criteria, pressing 'View Data' will list the selected data in the data window pane and pressing 'Export' will export the selected data to file. Only data in rows that match every set of criteria will appear in the data view window pane or the exported data set.

Subset selection criteria are presented in tabular form. Every selected parameter occupies a row in the criteria table. Each parameter can have one criteria expression such as 'depth > 200'. If you would like to apply more than one criteria expression to a certain parameter see Section 7.3 Extending Criteria Expressions.

The columns of the Subset Criteria are as follows:
Subset: checking this box includes the variable and it's criteria in the selected data. Unchecking the box excludes this variable and it's criteria from the selected data.
Parameter:  short name for the selected parameter (i.e. 'sta' for 'station number' parameter)
Description: a brief description of the data this parameter represents
Units:  reported units of measurement for this parameter
all values selecting all values allows any value to be recognized as valid
contains the value of the data must contain some value, i.e. contains TM would return all values containing the character string TM
> greater than
>= greater than or equal to
= equal to
<= less than or equal to
< less than (i.e. press < 500, would return all rows of data where pressure is less than 500)
Value: the value the previous Criteria selection should be applied to i.e. if Criteria is set to <= and Value is set to -2.4 the selected data will return all rows for this parameter where the value is less than or equal to -2.4
Remove nd:  this will eliminate all rows where this parameter does not have a value

Values can include integers (23 or -2), floating point numbers (1.375 or -32.0), text ('ttn-043'), or alphanumeric strings ('S4'). For instance, if one of the parameters is 'standard_station identifier' and only data that is desired by the user are data from station N7, the user can set the 'Criteria' column for the 'standard_station identifier' row to '=' and the 'Value' column to 'N7' (without the quotes otherwise it will look for text with single quotes around the text N7).

Parameters can be added to the criteria by selecting them from the catalog tree and pressing the 'Subset' button again. This will not drop previously defined criteria, and this process of add/removing parameters and redefining criteria may be repeated as many times as needed. After viewing or exporting the data, press 'Subset' to return to the criteria table and further refine you selection.

To clear all criteria, press the 'Reset Criteria' button that is displayed above the criteria table.

5.0 Viewing the Data

After defining selection criteria, if any, to view the selected data, press the 'View Data' button from the toolbar. JGView reads the data file and returns a table of rows that match the selection criteria. While the data is being read, JGView provides a progress monitor to indicate how much of the file has been read, the name of the file being read, and a 'Cancel' button that will abort the read operation and return to the criteria table. Having specific criteria makes the viewing process run quickly and efficiently.

When the table of selected data has been completed, the columns may be rearranged to any order by dragging them by their column headers. At this time, to export the selected data to a file, press the 'Export' button on the toolbar.

To return to your criteria table, press the 'Subset' button from the toolbar.

5.1 Viewing large data files

Some data files are very large (more than 20 MB). Loading large data files into memory might cause the computer to operate slowly, and JGView may run out of memory. The reason JGView runs out of memory is that the table in the data view pane that holds the selected data has become too large. If this occurs, JGView will notify you that the program has run out of memory and is unable to complete the viewing operation. This notification also provides the number of parameters that were being selected, the percentage of reading that JGView was able to complete, and the size in megabytes of the data file. This information should help to determine how much the selection criteria need to be refined. Even though viewing the data may cause these memory problems, exporting the data will always work regardless of file size. If you encounter a problem viewing the data, you still have the option of exporting large data selections.

5.2 Optimizing JGView

JGView runs within the Java Virtual Machine (JVM) which acts like its own operating system. The default memory space assigned to the JVM is 64 MB. With data files as large as 51 MB, the 64 MB available to JGView will be insufficient to view data from such large files. In order to increase the memory allocated to the JVM, some parameters need to be added to the execution command that runs JGView. Note: these parameters can only be used when running the JGView.jar file and cannot be used with the JGView.exe file. The JGView.exe file has these commands embedded, and since it is unknown what the memory limitations of the computer systems running JGView will be, the JGView.exe file has been set to allocate 128 MB of memory to JGView.

To run an optimized JGView, execute java from the installed path to run the JGView.jar file like so: 'java -Xmx256m -Xoptimize -jar JGView.jar'. This command assigns 256 MB to the JVM for JGView to use. This number can be any value provided it is smaller than the available memory for the computer system.

6.0 Exporting the Data

At any time after pressing the 'Subset' button, the selected data can be exported to file. If the data is currently being viewed in the data pane, the export will build the file from the dat view table, preserving the order of columns. If exporting directly from the Subset Criteria window, JGView reads the data file and applies the selection criteria during the export operation.

JGView will ask where it should save the file and in which format. Select the file format by choosing the file type just below the box labeled 'File name:'. The file formats are as follows:
Tab Separated (.tsv): each value is separated by the TAB character.
Comma Separated (.csv): each value is separated by the COMMA character.
Ocean Data View General (.*): TAB separated list with special headers for use with the Ocean Data View application. Replaces nd values with [blank] (nothing) and creates a .info header file.
Ocean Data View Generic (.txt): TAB Separated list with required parameters (date, time, sta, lat, lon, depth) for complete compatibility with the Ocean Data View application. Replaces nd values with [blank] (nothing) and creates a .info header file.

  Ocean Data View Home Page for ODV information and downloads
Matlab (.dat): TAB separated list of values to be imported into the Matlab application. This file format replaces nd values with 'NaN' and write Matlab compatible header lines.

  Matlab Home Page from The Mathworks, Inc.

After selecting a file name for Tab Separated or Comma Separated file formats, users are prompted to specify a character string to use for all 'nd' values. The predefined values you may select are blank (''), 'nd', 'Nan', or 'Other'. Selecting Other allows the user to specify their own character string for substitution. Once JGView has completed extracting the data to the specified file, a confirmation message is displayed to signify the data has been exported successfully. Do not open the exported file until receiving this confirmation message. Sometimes this confirmation window may be hidden behind the JGView window, if performing tasks in addition to JGView.

6.1 File Extensions

When choosing a filename for the exported data, the file will always be saved with the file extension related to the selected file format. For instance, if MATLAB (*.dat) has been selected and the specified filename is 'bottle_data', the export will be saved as 'bottle_data.dat'. The appropriate extension will be added to filenames unless the user has already done so or the selected file format is ODV General (*.*) which accepts filenames with any extension. If the user-specified filename includes a file extension which differs from the default extension for a selected file format, JGView will write the file out in the selected file format without changing the given extension.

6.2 Ocean Data View (ODV) File Format

Ocean Data View (ODV), developed by Dr. Reiner Schlitzer (Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany), is a software package for the interactive exploration, analysis and visualization of oceanographic and other geo-referenced profile or sequence data. ODV runs on Windows (9x, Me, NT, 2000, XP), UNIX (Solaris, Irix, AIX), Linux and Mac OS-X systems. The data and configuration files are platform-independent and can be exchanged between different systems.

ODV file format has some restrictions. If the exported ODV data file exceeds the maximum of 50 parameters, JGView will report how many parameters must be removed to continue. ODV Generic format is more restrictive, but is fully compatible with ODV and can be dragged over the ODV application icon to begin viewing the data with ODV.

6.2.1 ODV Generic Format

ODV Generic format requires that the following parameters be selected: year, event, sta or sta_std, lat or lat_n, lon or lon_n, and depth or press or depth_n. If one or more of these parameters is not selected, the user will be told which ones are missing. Many data files do not contain all of these parameters, and in these cases, ODV Generic is not an export format option.

  Ocean Data View Home Page for ODV information and downloads

7.0 Extending JGView

JGView can be run from any location on your computer and is not limited to operation from the CD. It is recommended that users copy the CD-ROM to their computer's hard disk. When doing so, the file structure does not need to be maintained as it exists on the CD. Any configuration of file structure across the computer is possible and advantageous for performance and extensibility.

7.1 Moving JGView off the CD-ROM

Considering the size of the data being processed, running JGView from a CD-ROM does not provide optimal performance, especially when viewing selected data. The directories used by JGView are /data, /docs, and /images. If JGView cannot locate these directories, it will prompt the user to locate them manually.

Note: JGView will always look two directories above its own location to find /data, /docs, and /images. If you wish to run JGView and use a /data directory on your hard disk, you must move the JGView application file to your hard disk as well. When JGView is run from the CD it will default to using the /data directory on the CD.

7.2 Importing Data

Running JGView on a /data directory stored on the computer's hard disk (as opposed to the CD-ROM), yields a performance gain, and an extensibility of the dataset as well. JGView creates the data catalog tree from the file structure of the /data directory. Therefore, you can alter the structure of the data catalog tree by modifying the file structure of the /data directory. By adding a new TSV file under the /data directory, JGView will read it and add it to the catalog to be browsed, searched, viewed, subsetted, and exported. The TSV files created from the export function of JGView can be saved into the /data directory, and on the next execution of JGView these files will appear in the catalog. See section 1.4 JGView Data Files for an explanation of how the application uses the data files.

7.2.1 TSV File Format

Your own TSV files can be placed under the /data directory. The format should be as follows:

The beginning of a TSV data file can have any number of comment lines beginning with the pound symbol '#'. These lines will form the documentation that is displayed in the documentation pane whenever this TSV file is selected from the data catalog tree. The next line after any comments, if any, should be a tab separated list of the parameter headers. Parameter headers can end with units defined as any value between brackets i.e. depth [m]            time [seconds]

All lines after the parameter line must be data values. All data values that are null should be represented with 'nd'. If they are not represented as 'nd', the criteria option for removing these 'no data values' will not work properly nor will the export replacement of these 'no data values'.

7.3 Extending Criteria Expressions

If JGView is running from the hard disk (Section 7.1 Moving JGView off the CD-ROM), JGView is capable of indirectly applying more than one expression of criteria to a given parameter. Because saving exported data to the /data directory is allowed, since it resides on your hard disk (Section 7.2 Importing Data), the exported file can be selected from the data catalog tree. The process is as follows:

1) Define the first set of criteria for the selected data
2) Export the data in TSV file format and save it under the /data directory on your hard disk
3) Refresh the Tree from the main menu 'File -> Refresh Tree'
5) Select your exported file from the data catalog tree
6) Apply the new set of criteria
7) Export the file

This process may be repeated until the desired results are achieved.

7.4 Refreshing the Data Catalog Tree

The data catalog tree can be altered as TSV files are either added to or removed from the /data directory. To reflect those changes without having to restart JGView, select 'Refresh Tree' from the Main Menu under 'File'. This function will drop the current tree, reread the directory and file structure, and build the tree again.

This function is useful when saving TSV files to the /data directory from previous exports. New data files that appear in the data catalog tree, may be processed in the same manner as all other data files.

8.0 Troubleshooting

JGView has been tested on the following operating systems: Windows 98/NT/2000/XP, MAC OS X, Linux Red Hat 7.3, SPARC 10 Solaris 7, SGI IRIX 6.5.

8.1 Starting JGView

When starting JGView, the program will always look for the /data directory two directories above wherever JGView has been started. For instance, if JGView was started from the /java directory on your local computer instead of starting JGView from the /applications/Common directory on the CD, a file chooser will ask for the location of the /data directory. When this occurs, navigate to the directory that contains that /data directory, highlight the /data directory with a single-click, then click the button labeled 'Open'.

If the /images or /docs directory is not in the same directory that /data was located, the same file prompt will ask for the location of each of these directories. Navigate to wherever they reside, highlight the directory, then click 'Open'.

If a directory is selected that is not the directory JGView is looking for, the file chooser will ask to find the directory again. If you are sure you have the correct directory, JGView is looking for specific files in each to verify that you have selected the correct directory. In the case of the /data directory, JGView looks for the 'param_master.dct' file, /images looks for the 'datarealm.gif' file, and /docs looks for the 'site_map.htm' file.

Note: Rearranging any of the files in these directories will affect how JGView operates. Adding files to these directories does not affect JGView, rather by adding .TSV files to the data directory, a user can include their own data files within the data catalog tree. See section 7.2 Importing Data for more information.

8.2 Selection Problems

If at any time, the selection of data does not operate as it normally would, we suggest you start over by selecting 'File -> Start Over' from the Main Menu. If this does not clear the problem, try using 'File-> Refresh Tree'. If this doesn't work, restart JGView by exiting the program and running it again. If the problem still persists and you think you have found a bug, please contact the developers at the CD-ROM technical support page .

8.3 Out of Memory Errors

Out of Memory errors should only occur when trying to view a data file. There is a correlation between the number of selected parameters, the criteria used to subset the data file, and the size of the data file. Please see section '5.1 Viewing large data files' for information on how to remedy this situation.

8.4 Browser Problems

The only JGView function that is not platform independent is the display of data file information in the system's default browser. The browser functions have been tested on Windows 95/2000/NT/XP, Mac OS X, Linux, Solaris and SGI IRIX. These tests have repeatedly demonstrated that different operating system configurations do produce different results when JGView launches the web browser application. If necessary, it is possible to view the data file's documentation independently of JGView. Each data file's corresponding html file resides in the same file system path displayed in the border of the documentation pane. For example, if the user wanted to view the html documentation for the N_uptake_atlantisII file, but the browser would not launch from JGView, look at the Documentation border to see that the data file resides at /North_Atlantic/Chemical/Chem/N_uptake_atlantisII. In the Chem directory, there will be a file called N_uptake_atlantisII.htm. You can use your browser external to JGView to view this file.

8.5 Export Problems

If JGView reports an error during export, check to see whether the file might have been created anyway. Some errors are not fatal. If a fatal error is encountered, try selecting 'Start Over' from the 'File' menu. If JGView still returns an error, please contact the JGView development team.