CUBEVIEW(1)

👑 CUBEVIEW(1) — the Yorick era ✨

okay bestie, sit down, hydrate, because we're about to look at some 3D FITS files and it's gonna be adorable 🫶 (this one lives in the Yorick manual, section 1, iykyk)

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🌈 NAME 🌈

cubeview — literally just: view 3D FITS files 💅

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✨ SYNOPSIS ✨

cubeview [--pixel[=0/1]] [--stand-alone[=0/1]] [--ui=ui] [file]
or yorick -i cubeview.i [options] [file]
or from within yorick(1): cubeview,options or cv_gtk[,options].

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💖 DESCRIPTION 💖

Cubeview is a 3D data viewer that is specialized in spectro-imaging — main character energy only — and it's implemented using the Yorick interpreted language (go read yorick(1), bestie). So what even is a 3D data cube here? It's a three-dimensional array of numbers, and usually those numbers are chilling inside a FITS file. Simple as that. 🍓

It can do its thing two ways:

• as a stand-alone viewer for viewing 3D FITS files — in which case you don't need to know much about Yorick to use it, no gatekeeping here 💅
• as a Yorick package, in which case it's possible to view Yorick arrays directly 👑

And here's the fun part: Cubeview can be customized and enhanced through "hooks" which can automatically perform custom actions while the cube is being viewed. For instance, it is possible to overplot some complex contour map over the slice view each time it is refreshed. Obsessed, honestly. For more details about the cubeview API in Yorick, read cubeview.i. 📖

Also, when cubeview is launched from a terminal window, it is possible to type Yorick commands in that window almost at any time. And in the following, this manpage assumes the reader is not a regular Yorick user — so if that's you, welcome, you're safe here 🫶

Since Cubeview is specialized in spectro-imaging, it assumes the first two dimensions of the cube are of spatial nature while the third is spectral. Cubeview is able to correclty interpret the FITS headers of data produced with the decommissioned BEAR instrument which used to be operated at CFHT and SINFONI currently operated at ESO VLT. Other data may be interpreted if they follow the same conventions. But listen — if the FITS header cannot be interpreted, the axes in the plots cannot be trusted 😭, though you can still explore the 3D cube. So like, vibe check the axes, fr fr.

Cubeview uses three windows: a toolbox, a slice image window and a spectrum plot window. The toolbox allows one to open a new FITS file, save the currently selected sub-cube (determined both by the spectrum and slice being viewed), set various display parameters, and perform various actions — most notably selecting a new spectrum or a new slice. And if file is set in the calling sequence, then all three windows open at once, else only the toolbox appears at first, allowing the user to select a file to read. ✨

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🎀 MAIN PAGE 🎀

The Main page in the toolbox offers reasonably self-explanatory buttons to perform various actions. (Reasonably!! we're being honest here 💀)

To select a new slice, click on Slice in the Select frame, then drag the mouse pointer over the region of interest in the spectrum window. Conversely, a new sepctrum is selected by first clicking Spectrum and then using the mouse in the slice window.

Now, how you use the mouse for selecting a spectrum depends on the Aperture type selected in the Spectrum property page:

• Circular — left button: click to select new center; right button: drag from new center to new edge;
• Square — left button: click to select new center; right button: drag from new center to new edge;
• Rectangular — drag from one corner to the opposite.

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🧚 SPECTRUM PAGE 🧚

The Spectrum property page allows one to select the Aperture type mentioned above. In addition, if the FITS header has been interpreted correctly, it is possible to switch the spectral axis between:

• Wavelength
• Frequency
• Channels (raw indices in the cube — the only meaningful value if the header was not interpreted correctly 🙈)
• Velocity relative to a Reference wavelength which can also be set on this page

And Smoothing FWHM controls whether the displayed spectrum should be Gaussian-smoothed to increase the apparent signal-to-noise. Glow-up via math, we love to see it 💅

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🌸 SLICE PAGE 🌸

The slice can be displayed in two modes.

The most usual one (named Normal (palette) in Cubeview) is palette-based. The corresponding Color palette can be selected among the standard Yorick ones. 🎨

Alternatively, Cubeview can produce three-color images using virtual, overlapping red, green and blue filters. The slice can then be displayed either at 8 or 24 bit color-depth. 24 bit color depth is usually better, but 8 bit is useful to save to some image formats, which you can do from the Yorick command line. And Smoothing FWHM and Oversampling control two means of smoothing the displayed image for eye candy. ✨

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💅 OPTIONS 💅

• --pixel[=(false|true)] — Control whether the slice window axes are in pixels (true) or in world coordinates as indicated by the CDELT, CRPIX and CRVAL FITS cards. --pixel is equivalent to --pixel=true. The default is true. 📍
• --stand-alone[=(false|true)] — Control whether closing the toolbox window exits Yorick. --stand-alone is equivalent to --stand-alone=true. This is the default for he first form of invocation. If set to false, it is necessary to type "quit" at the Yorick prompt to completely quit the application. 🚪
• --ui=(gtk|tws|text) — Control the look-and-feel of the toolbox. The default toolbox uses the GTK toolkit, and requires several software components in addition to Yorick (python, pygtk and libglade). An alternative toolbox coded entirely in Yorick is also available. It uses the "TWS" package to draw buttons and other widgets. It is uglier, but more portable, than the GTK-based toolbox. Finally, it is possible to completely control cubeview from the Yorick prompt, in "text" mode. Type "cv_library" for a list of available commands. 🎛️

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🔥 SEE ALSO 🔥

yorick(1), cubeview.i

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💜 AUTHORS 💜

Thibaut Paumard <paumard@users.sourceforge.net>

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okay and that's the whole thing, bestie!! this page is from the Yorick manual — CUBEVIEW(1) — dated 2008-01-03, and it ate, no crumbs left. go view those cubes, you're the main character now 👑💖🦋