Status of GMT 5 October 30, 2012

Paul Wessel, SOEST, UHM W.H.F. Smith, R. Scharroo, J. Luis, F. Wobbe

EarthCube End-User Domain Workshop for EarthScope Funded since 1993

gmt.soest.hawaii.edu

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GMT Version 5

• What is new in GMT 5?

‣ Big rewrite under the hood

‣ Switched to cmake for cross-platform

installation

• What is in it for the users?

‣ New tools and more options

• What is in it for developers?

‣ API access to GMT functions

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New features for users

• Better GIS interoperability:

‣ Import/Export OGR/GMT files

✴ogr2ogr supports a new OGR/GMT ASCII file

format developed by Brent Wood (NIWA) and

Paul Wessel, and implemented by Frank

Warmerdam [now at Google]

✴The OGR/GMT format retains all metadata and

may be considered an “ASCII shapefile”

‣ Bridge to GDAL for rasters

✴GMT5 can read any grid format supported by

GDAL, and can also read images

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New features for users

• Multi-core support in some tools

‣ Relies on OpenMP via GCC

• Improved consistency and flexibility for table i/o

across GMT:

‣ All programs now use same uniform i/o library

with support for multi-segments across GMT

‣ New global options –i and –o allows users to

select which columns to read and write

‣ Enhanced option –b allows free-form native binary

files to be read and written

‣ netCDF files can be used directly [read-only]

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New features for users

• Several new tools and many new options:

‣ PDF transparency

‣ Automatic annotation selection

‣ Run-time choice of FFT algorithms

‣ Run-time choice of triangulation algorithms

‣ 3-D perspective view available in all programs

‣ New enhanced macro language for custom

symbols with multiple variables

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News for developers

• GMT 5 has turned all GMT 4 programs

into a high-level API, allowing easy

access to GMT functionality from

custom programs

• The GMT API is released under the

lesser GNU license, broadening its

potential use

• We are developing a Matlab/Octave

interface and will start development of

a Python API thereafter

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GMT 4

netCDF

pslib

GMT

GMT Program

• GMT 4 library is fairly low-level

• High-level functionality in GMT

programs

• Lots of global variables throughout

• Inconsistent development; no docs

GDAL

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GMT 5

GMT Application

• GMT 5 API has new functions to

manage GMT sessions, options, and

data i/o

• GMT module library contains a set of

GMT functions called modules

• Modules replicate behavior of a GMT 4

program in a single function

• The familiar GMT programs are now so

simple they are built on-the-fly from a

short template program

GMT 5 API

netCDF

GMT

GDAL

Modules

GMT Program

PSL

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GMT 5 API

• Creates a self-contained, thread-safe GMT session (or several sessions, eventually running in parallel)

• Registers data sources and destinations (e.g., streams, memory locations) if they are not regular files

• Manages program options via linked option lists or text arrays (e.g., argc, argv[])

• Imports data sources into memory

• Calls one or more GMT modules

• Exports results from memory to files

• Destroys the session and all its resources

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Custom Applications

• Rapid deployment for new applications that need

GMT procession or plotting

• Heavy lifting is done by API and the modules

• Custom code can create and manipulate the five

GMT data structures (GMT grids, images, data

tables, text tables, and CPT texture tables) that

the API currently recognizes

• C/C++ API will be released first, followed by

Matlab/Octave and Python APIs

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GMTSAR http://topex.ucsd.edu/gmtsar/

Comments/Concerns • GMT is software engineering, no CI expert involvement

• Heavy use of volunteers, who change over time

• Funded by NSF MGG but large user base in GEO

• Focal mechanism plot not in core GMT but unsupported

supplement

• GMT goals driven by selfish needs and user requests

• Emphasis on longevity, portability, standards, quality

graphics

• What is needed to better support EarthScope/Cube:

• Paid/volunteer Python-enabled domain scientist, or

• Paid/volunteer Python-enabled programmer

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GMT 5 Schedule

• A beta version (5.0.0b) was released on

August 25, 2011

• Current developmental GMT5 is always

available via our subversion repository and is

quite stable

• GMT 5.0.0 will be released in early 2013,

pending more testing and documentation

• Visit www.soest.hawaii.edu/gmt5 to learn

more and participate in our new GMT Logo

contest and win a GMT T-shirt!