ncBrowse: A Graphical netCDF File Browser Donald Denbo NOAA-PMEL/UW-JISAO

July 9, Western Pacific Geophysics Meeting Wellington, New Zealand2 Introduction ncBrowse is a Java Application designed to graphically browse data files in netCDF format. netCDF is available from Unidata and is …Unidata 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, Western Pacific Geophysics Meeting Wellington, New Zealand3 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, Western Pacific Geophysics Meeting Wellington, New Zealand4 Features SGT graphics for 1 and 2 dimensional cuts through data SGT graphics 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

Vector Demonstration

July 9, Western Pacific Geophysics Meeting Wellington, New Zealand10 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, Western Pacific Geophysics Meeting Wellington, New Zealand11 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, Western Pacific Geophysics Meeting Wellington, New Zealand12 Mapping Examples Line Plot Where i, the depth index, varies. Grid Plot Where i, j, the latitude and longitude indices, vary, and k is held constant. Vector Plot Where i, k, the x-axis and depth indices, vary and j, m are held constant.

July 9, Western Pacific Geophysics Meeting Wellington, New Zealand13 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, Western Pacific Geophysics Meeting Wellington, New Zealand14 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.VisAD

July 9, Western Pacific Geophysics Meeting Wellington, New Zealand15 Availability NcBrowse is freely available from the ncBrowse web page, at and includes: Download options for Mac, PC, and Unix (notice that V1.3.3Beta5 includes the Java Virtual Machine) Users Archive (ncBrowse related discussions and questions) News and updates On-line help