Developer(s) | Marc Schellens |
---|---|
Initial release | 2004 |
Stable release | |
Repository | |
Written in | C++ (wxWidgets) |
Operating system | Linux, macOS, Solaris, POSIX, Windows |
Type | Technical computing |
License | GNU GPL-2.0 |
Website | github |
The GNU Data Language (GDL) is a free alternative to IDL (Interactive Data Language), [2] [3] [4] achieving full compatibility with IDL 7 and partial compatibility with IDL 8. [5] Together with its library routines, GDL is developed to serve as a tool for data analysis and visualization in such disciplines as astronomy, [6] geosciences, and medical imaging. GDL is licensed under the GPL. Other open-source numerical data analysis tools similar to GDL include Julia, GNU Octave, NCAR Command Language (NCL), Perl Data Language (PDL), R, Scilab, SciPy, and Yorick.
GDL as a language is dynamically-typed, vectorized, and has object-oriented programming capabilities. GDL library routines handle numerical calculations (e.g. FFT), data visualisation, signal/image processing, interaction with host OS, and data input/output. GDL supports several data formats, such as NetCDF, HDF (v4 & v5), GRIB, PNG, TIFF, and DICOM. Graphical output is handled by X11, PostScript, SVG, or z-buffer terminals, the last one allowing output graphics (plots) to be saved in raster graphics formats. GDL features integrated debugging facilities, such as breakpoints. GDL has a Python bridge (Python code can be called from GDL; GDL can be compiled as a Python module). GDL uses Eigen (C++ library) numerical library (similar to Intel MKL) to offer high computing performance on multi-core processors.
Packaged versions of GDL are available for several Linux and BSD flavours as well as Mac OS X. The source code compiles on Microsoft Windows and other UNIX systems, including Solaris.
GDL is not an official GNU package.
IDL, short for Interactive Data Language, is a programming language used for data analysis. It is popular in particular areas of science, such as astronomy, atmospheric physics and medical imaging. IDL shares a common syntax with PV-Wave and originated from the same codebase, though the languages have subsequently diverged in detail. There are also free or costless implementations, such as GNU Data Language (GDL) and Fawlty Language (FL).
109 Virginis is a single, white-hued star in the zodiac constellation of Virgo, located some 134.5 light years away from the Sun. It is the seventh-brightest member of this constellation, having an apparent visual magnitude of +3.72.
Gamma Volantis, Latinized from γ Volantis, is a wide binary star system in the southern constellation of Volans. Based upon parallax measurements, it is approximately 133 light years from Earth. It is bright enough to be seen with the naked eye and can be found around 9° to the east-southeast of the Large Magellanic Cloud.
28 Andromedae is a Delta Scuti variable star in the constellation Andromeda. 28 Andromedae is the Flamsteed designation. It also bears the variable star name GN Andromedae. Its apparent magnitude is 5.214, varying by less than 0.1 magnitudes.
70 Aquilae, abbreviated 70 Aql, is a single orange-hued star in the equatorial constellation of Aquila. 70 Aquilae is its Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.90. The distance to 70 Aquilae, as determined from its annual parallax shift of 3.5 mas, is around 940 light years. The star is moving closer to the Earth with a heliocentric radial velocity of −9 km/s.
UU Aurigae is a carbon star in the constellation Auriga. It is approximately 341 parsecs from Earth.
28 Cancri is a star system in the zodiac constellation of Cancer. It is a variable star with the designation CX Cancri, and is close to the lower limit of visibility with the naked eye, having a mean apparent visual magnitude of 6.05. The annual parallax shift seen from Earth's orbit is 7.32 mas, which provides a distance estimate of about 450 light years. It is moving away from the Sun with a radial velocity of around +9 km/s.
3 Centauri is a triple star system in the southern constellation of Centaurus, located approximately 300 light years from the Sun. It is visible to the naked eye as a faint, blue-white hued star with a combined apparent visual magnitude of 4.32. As of 2017, the two visible components had an angular separation of 7.851″ along a position angle of 106°. The system has the Bayer designation k Centauri; 3 Centauri is the Flamsteed designation. It is a suspected eclipsing binary with a variable star designation V983 Centauri.
HD 13189 is an 8th magnitude star in Triangulum constellation.
NO Aurigae is a pulsating variable star in the constellation Auriga.
2 Ceti is a single star in the equatorial constellation of Cetus, near the border with Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.483. The distance to 2 Ceti can be estimated from its annual parallax shift of 12.0 mas, which yields a value of around 272 light years. It appears to be moving further from the Earth with a heliocentric radial velocity of about +8 km/s.
Tau1 Hydrae is a triple star system in the equatorial constellation of Hydra. Based upon the annual parallax shift of the two visible components as seen from Earth, they are located about 18 parsecs (59 ly) from the Sun. The system has a combined apparent visual magnitude of +4.59, which is bright enough to be visible to the naked eye at night.
Tau2 Hydrae is a probable astrometric binary star system in the equatorial constellation of Hydra. Based upon an annual parallax shift of 6.30 mas as seen from Earth, it is located around 520 light years from the Sun. The brighter component is visible to the naked eye with an apparent visual magnitude of +4.56.
10 Leonis Minoris is a single, variable star in the northern constellation Leo Minor, located approximately 180 light years away based on parallax. It has the variable star designation SU Leonis Minoris; 10 Leonis Minoris is the Flamsteed designation. This body is visible to the naked eye as a faint, orange-hued star with a baseline apparent visual magnitude of 4.54. It is moving closer to the Earth with a heliocentric radial velocity of −12 km/s.
Astropy is a collection of software packages written in the Python programming language and designed for use in astronomy. The software is a single, free, core package for astronomical utilities due to the increasingly widespread usage of Python by astronomers, and to foster interoperability between various extant Python astronomy packages. Astropy is included in several large Python distributions; it is part of package managers for Linux and macOS, the Anaconda Python Distribution, Enthought Canopy and Ureka.
π2 Gruis, Latinised as Pi2 Gruis, is a binary star system in the southern constellation of Grus. It is faintly visible to the naked eye as a yellow-white hued star with an apparent visual magnitude of 5.622. Based upon an annual parallax shift of 25.1 mas as seen from the Earth, the system is located 130 light years from the Sun.
BI Cygni(BI Cyg, IRC +40408, BD+36 4025) is a red supergiant in the constellation Cygnus. It is an irregular variable star with a maximum brightness of magnitude 8.4 and a minimum of magnitude 9.9. It is considered a member of the stellar Cygnus OB1 association, its distance is around 1,400 parsecs of the Solar System. It is less than a degree south of another variable red supergiant, BC Cygni.
Alruba, a name derived from Arabic for "the foal", is a suspected astrometric binary star system in the northern circumpolar constellation of Draco. It is just barely visible to the naked eye as a dim point of light with an apparent visual magnitude of 5.76. Based on parallax measurements obtained during the Gaia mission, it is located at a distance of about 457 light-years from the Sun. The system is drifting closer with a radial velocity of −2 km/s.