IUGG 2003 SW05 (Thu Jul 10 2003)

GTOOL: I/O Library and Analysis Tool for Gridded Data

Eizi TOYODA*1, Shin-Ichi Takehiro*2, Masaki Ishiwatari*3, and Yoshi-Yuki Hayashi*4



First Generation
Second Generation

GTOOL3 Overview

GTOOL3 Data Structure

File Format
Header Record
Unification of Data and Axes
Visualization Headers
NAMEfor datafor axis
DMINlowest contour levelpreferred plot range (lower)
DMAXhighest contour levelpreferred plot range (upper)
DIVScontour interval (thin)tick mark interval (small)
DIVLcontour interval (bold)tick mark interval (large)
STYP(not used)log plot / upside-down flags

GTOOL3 Software Structure

Software Overview

module structure of GTOOL3 library.

Modular Coding Style

Adopted from DCL
GTOOL3 Progress

Interface Design

GFTOOL File input/output
GPTOOL: header-data pair as an data object
GGTOOL: header-data pair as an graphic object

Commandline Tool Support

gtool4 project

Generalization vs. Specialization

GTOOL3 Limitations

New Infrastructure Employed

overview of gtool4 software products

gtool4 Data Structure

Data structure defined by "gtool4 NetCDF Conventions"

Visualization Attributes

schematic illustration of structure variable

Visualization Class Structure

visualization class in gtool4 NetCDF Conventions.

Compatibility to Existing Conventions

Technique to assure interoperability

Attr Creation _ UseAdvisedRecommendedMandatory

gtool4/Fortran90 Implementation


Modular design

module structure of gtool4 library.

Data I/O Interface

gtool_history interface

Simpler, more intuitive, thus more specialized than GTOOL3

Visualization Interface

schematic illustration of structure variable

Screenshot of gtool4 GUI Frontend (left) and gtview contoring/shading result (right)

Practical Fortran 90 Coding Style

Object-oriented module
Header module
Variable-length character string
Regular expression in Fortran



Cooperative Ocean/Atmosphere Research Data Service, 1995: COARDS Convention: http://ferret.wrc.noaa.gov/noaa_coop/coop_cdf_profile.html
Decyk, V. K., C. D. Norton, and B. K. Szymanski: Expressing Object-Oriented Concepts in Fortran 90. ACM Fortran Forum, vol. 16, num 1, pp. 13-18, April 1997.
Eaton, B., 1997: NCAR-CSM NetCDF Conventions. http://www.cgd.ucar.edu/cms/eaton/netcdf/NCAR-CSM.html
GFD Dennou Club, 1992-2002: DCL (GFD Dennou Club Library). http://www.gfd-dennou.org/arch/dcl
Gregory, J., Bob Drach, and Simon Tett, 1999: GDT netCDF conventions for climate data, version 1.3. http://www-pcmdi.llnl.gov/drach/GDT_convention.html.
University Corporation for Atmospheric Research/Unidata, 1993-1999: NetCDF. http://www.unidata.ucar.edu/packages/netcdf/index.html
Swamp project, 1998: AGCM5. http://www.gfd-dennou.org/arch/agcm5, GFD Dennou Club.
Toyoda, E., Ishiwatari, M., Takehiro, S., Hayashi, Y.-Y., gtool4 Devlopment Group, 2002: gtool4 Fortran90 Tools/Library, http://www.gfd-dennou.org/arch/gtool4/, GFD Dennou Club.
Toyoda, E., Ishiwatari, M., Horinouchi, T., Akahori, K., Numaguti, A., Hayashi, Y.-Y., GFD Dennou Club Davis Project, 2000: gtool4 netCDF convention, http://www.gfd-dennou.org/arch/gtool4/, GFD Dennou Club.
Muroi, C., E. Toyoda, H. Yoshimura, M. Hosaka, M. Sugi, 2002: Standard Coding Rule. Tenki, vol. 49, num. 1, pp. 91-95. http://www.mri-jma.go.jp/Dep/fo/mrinpd/coderule.html

*1Numerical Prediction Division, Japan Meteorological Agency
*2Faculty of Sciences, Kyushu University
*3Graduate School of Environment Earth Sciences, Hokkaido University
*4Graduate School of Science, Hokkaido University