Waterfall plot

{{Short description|Data visualization technique}} {{distinguish|text=[[Waterfall chart]]s, 2D floating-column diagram showing increases and decreases.}} {{redirect|Waterfall display|the hardware|Waterfall display (hardware)}} [[File:SDRpp FM subcarriers.png|thumb|300px|right|FM station broadcasting at 91.7 MHz on seen on SDRpp spectrogram]] '''Waterfall plots''' are often used to show how two-dimensional phenomena change over time.{{cite web |last1=Glen |first1=Stephanie |title=Waterfall Plot / Chart: Definition, Types & Examples |url=https://www.statisticshowto.com/waterfall-plot/ |website=statisticshowto.com |date=11 January 2018 |access-date=13 October 2021}} A three-dimensional ''spectral waterfall plot'' is a plot in which multiple curves of data, typically [[Spectrum|spectra]], are displayed simultaneously. Typically the curves are staggered both across the screen and vertically, with "nearer" curves masking the ones behind. The result is a series of "mountain" shapes that appear to be side by side. The waterfall plot is often used to show how two-dimensional information changes over time or some other variable such as [[rotational speed]]. Waterfall plots are also often used to depict ''[[spectrogram]]s'' or ''cumulative spectral decay''{{Definition needed|date=December 2021}} (CSD).

==Uses==

• The results of [[spectral density estimation]], showing the spectrum of the signal at successive intervals of time.
• The [[Latency (audio)|delayed response]] from a [[loudspeaker]] or [[listening room]] produced by [[impulse response]] testing or [[MLSSA]].
• Spectra at different engine speeds when testing engines. [[Image:Aaronia Spectrum Analyzer Software.jpg|thumb|The upper half of this diagram shows the frequency spectrum of a modern [[Switched-mode power supply|switching power supply]] which employs [[spread spectrum]]. The lower half is a waterfall plot showing the variation of the frequency spectrum over time during the power supply's heating up period.]] [[Image:Waterfall plot of a whistle.png|thumb|center|500px|Spectrogram and 3 styles of waterfall plot of a whistled sequence of 3 notes vs time]]

==See also==

• [[Loudspeaker acoustics]]
• [[Loudspeaker measurement]]

==References== {{Reflist}}

==External links==

• [http://blog.prosig.com/2007/06/24/measuring-torsional-crank-shaft-jitter/ Typical engine vibration waterfall]
• [http://vibrationdata.wordpress.com/2012/10/18/waterfall-fft/ Waterfall FFT Matlab script]

{{DEFAULTSORT:Waterfall Plot}} [[Category:Plots (graphics)]] [[Category:Audio engineering]] [[Category:Broadcast engineering]] [[Category:Sound production technology]] [[Category:Sound recording]] [[Category:Acoustics]]