ncBrowse: A Graphical netCDF File Browser

Donald DenboNOAA-PMEL/UW-JISAO

http://www.epic.noaa.gov/java/ncBrowse

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Introduction ncBrowse is a Java Application designed to

graphically browse data files in netCDF format. netCDF is available from Unidata and is …

Widely adopted by the oceanic and atmospheric communities

Machine-independent format Array-oriented Self describing Available for the Java, C, C++, and Fortran

languages

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Overview ncBrowse provides

Flexible, interactive graphical displays of data Tree and table views of netCDF file schema and

attributes Supports a wide range of netCDF conventions

COARDS – oceanic/atmospheric data sets (gridded) EPIC – oceanic observations, profile and time series

Next release will provide network access to DODS data files

ncBrowse has been downloaded 4749 times to 2265 unique sites in 55 countries as of July 1, 2002.

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Features SGT graphics for 1 and 2 dimensional cuts through data Handles files with character variables. Handles dimensions without associated variables Properly decodes several time formats Access to remote data files via DODS (beta version). Direct access to remote netCDF files from the Web (even

without DODS). Vector plots (beta). Variable mapping (beta). Animations by varying parameters in Variable Map (beta). Available for UNIX, Win32, and MacOS Graphics appearance easily modified Printing support

Virtual Demo

Virtual Demo

Virtual Demo

Virtual Demo

Vector Demonstration

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Design Goals Easy to use.

Graphical user interface designed to provide a “natural” navigation through netCDF file contents.

Platform neutral. Operates on UNIX, Win32, MacOS X, and MacOS 9.x (v1.0 only).

Independence from netCDF conventions. Does not require netCDF files to conform to a specific

convention. Does recognize some conventions, if present. For example,

EPIC and COARDS time conventions. Easy to compare netCDF files.

Multiple netCDF files and graphics windows can be simultaneously open

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Variable Mapping Update data handling to support variable mapping. Support

Line plots assigning any two variables or dimensions Grid plots. Vector plots.

Parametric plots. For example, temperature vs. salinity, with depth the

parameter. Flexible mapping of independent variables to graphical

axes. For example, a file that contains lat, lon, and temp as

separate netCDF variables could be mapped so that lat -> y-axis, lon -> x-axis, and temp -> z-axis.

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Mapping ExamplesLine Plot

Where i, the depth index, varies.

Grid PlotWhere i, j, the latitude and

longitude indices, vary, and k is held constant.

Vector PlotWhere i, k, the x-axis and depth indices, vary and j,

m are held constant.

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Future Directions(version 1.4 and beyond)

Color palette control Set range for colorbar Use zoomed range of graph for colorbar range

Improved graphics capabilities. Contour plot control (editing color map,

contour levels, etc.) Co-plotting variables

Global and variable attribute editing. Modification of local netCDF files.

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Future Directions(version 1.4 and beyond)

Allow mouse interrogation of data values.

Logarithmic axis support. Full access to OPeNDAP (formerly

DODS) servers. 3-D visualizations using VisAD.

July 9, 2002 2002 Western Pacific Geophysics Meeting Wellington, New Zealand

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Availability NcBrowse is freely available from the

ncBrowse web page, at http://www.epic.noaa.gov/java/ncBrowse and includes:

Download options for Mac, PC, and Unix (notice that V1.3.3Beta5 includes the Java Virtual Machine)

Users E-Mail Archive (ncBrowse related discussions and questions)

News and updates On-line help