Data AcQuisition And Real-Time Analysis
Scope - Spectrum - Spectrogram - Signal Generator
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The following is from the Daqarta Help system:



Spectrum Analyzer

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Spectrogram / Pitch Track Display Mode

Controls: Sgram/PT Dialog >> Scan/Scroll/Bloom
Macro: SgMode=Scan, Scroll, or Bloom


The Scan, Scroll, and Bloom buttons near the top of the Sgram/PT dialog control the way the spectrogram or pitch track display is shown.

In Scan mode, the spectrogram is always drawn from left to right, with a "wiper" bar at the leading edge where any prior image is being overwritten. In an ongoing (live or unPaused file) spectrogram, when the screen has been completely drawn and the bar passes the right edge, it wraps around to the left edge and continues overwriting the prior image.

In the default Scroll mode, the newest live or unPaused data appears at the right edge, with older data scrolling continuously to the left until it vanishes at the left edge.

Bloom is a "special effects" mode, not useful for analysis. New live data appears at the center of the screen and spreads symmetrically outward to vanish at left and right edges. This produces "hypnotic" or "psychedelic" visual effects (see below). No X axis is shown in Bloom mode.

File Analysis With Scan and Scroll:

After loading a DDisk (long) file, the display defaults to Pause mode. You can move through the file, as noted under Reading DDisk Files, via <> to move one step (screen column) at a time, or SHIFT+<> to move by one screen at a time, or ALT+<> to move by the user-adjustable Read Step Size. Home moves to the start of the file, and End moves to the last screen. You can also jump to specific locations via direct entry into the file position readout.

A position readout at the right end of the screen shows the file position (in whatever units are selected) of the start (left edge) of the screen. Below it is a separate readout showing the current end (right edge) of the screen. These are updated at the end of the key-initiated motion.

Although these commands work in any mode, as noted above no X axis is shown in Bloom mode... it's not intended for file analysis, though you can still move through it to find a particular location.

When you unPause, the file will appear to "run" as if live, though without producing sound. In Scroll (or Bloom) mode, both readouts are continuously updated as new columns scroll in, and old ones scroll out.

In Scan mode, the readout behavior is slightly different: The upper readout still shows the file position of the start of the screen, but in Scan mode that doesn't change until the "wiper" bar completes a full screen scan and wraps back. The lower readout shows the current bar position in the file, which is continually updated as the bar scans along.

Scan mode has one important use that Scroll doesn't support, which is triggered operation when unPaused. (In unPaused Scroll or Bloom modes, Trigger is forced off and disabled.) If your file has long quiet sections between events of interest, you may be able to set the trigger parameters to show only those events. This can greatly compress the display of the file, although the X-axis will no longer show meaningful timing info due to the omitted sections.

Bloom Visual Effects:

To see the mesmerizing visual effects of Bloom mode, toggle Trigger off and load CrankFM.GEN in the Generator control dialog. With the Generator on in Spectrogram mode, Bloom shows a surreal "landscape", like zooming through city streets lined with tall buildings... and fingerprints.

But the most surreal part happens after you watch this for a while, then look down at your keyboard. (Or Pause the display.) Things seem to contract briefly, as your vision adjusts.

You can make this effect much more pronounced by using a Generator setup that produces strong vertical features in the spectrogram. Composer.GEN is a good choice, and interesting in its own right. AMnoise.GEN also has prominent vertical features, though not very interesting to watch (or hear).

Now when you stop viewing the Bloom spectrogram, the visual contraction goes on for several seconds.

(Scroll mode can produce a much milder sideways motion upon stopping.)

Another good source of strong vertical features is DaqMusiq, and it's much more interesting to listen to. The included DaqMusiq mini-app macro takes care of all the settings... just hit the F8 key, then 'd'. When prompted to select a file, hit ESC to get the default GlossyTracks setup. (Or the most recently-used setup.)

Macro Notes:

You can set the spectrogram mode via SgMode=Scan, SgMode=Scroll, or SgMode=Bloom.

Alternatively, you can use SgMode=n, where n = 0 for Scan, 1 for Scroll, or 2 for Bloom.

See also Spectrogram / Pitch Track (Sgram/PT), Spectrogram / Pitch Track Controls


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