GSP

Performs general signal processing for aeroacoustic analysis.

Syntax

GSP(“name”) { parameters}

Qualifier

User-given name

Parameters

type (enum)
Surface or probe, specifying the type of signal processing to perform.
name (string)
User-given name of the command. The instance of a given command is referenced using this parameter.
resultFile (string)
Required data file, .h3d file for type=surface, .csv file for type=probe.
outGspFname (string)
Output file name (extension .gsph5) for writing when type=surface.
partName (string)
Specified surface name to perform the processing when type=surface.
useCellData (boolean)
Specification of cell or point data. useCellData is default.
dataArrayName (string)
Data to be processed should be set to “pressure” for all GSP applications.
timeRange (array)
Two element array specifying the minimum and maximum input time range, format: [min, max].
bandType (enum)
Band type to specify the frequency agglomeration; narrow_band (type=probe only) single_band, octave, 1_over_3_octave, 1_over_8_octave (type=probe only), 1_over_12_octave.
scale (enum)
Scale, or weighting factor used to weight the SPL output, default dB. scale= “” (dB weight), scale=A (dBA weight), or type=C (dBC weight).
frequencyRange (array)
Two element array specifying the minimum and maximum output frequency range, format: [min, max]. When bandType=single_band, the min and max are used to compute the bounds of the frequency. When bandType= octave, 1_over_3_octave, 1_over_12_octave, octave bands between the min and max frequency will be selected, including the overlapping bands above and below min, max frequency.
surfaceMapType (enum)
Type of surface map to compute; surfaceMapType=0 gives hydrodynamic dB map, surfaceMapType=1 gives band filtered animation, surfaceMapType=2 gives both outputs.
exportData (enum)
Type of display file to export, exportData=0 does not generate output display files, setting exportData=1 gives .png files, exportData=2 gives a .mp4 file of the animated results.
exportStride (integer)
Number of frames to increment when storing images or animation, providing the stride (increment) between frames of the output, used when exportData= 1|2.
exportDataFilename (string)
Used when exportData= 1 | 2, providing the output file name of the image or animation to be stored. Do not include extension in the file name, will be automatically provided.
exportResultType (enum)
Type of results to output for display; exportResultType=0 gives input signal (Pressure vs. Time), exportResultType =1 gives hydrodynamic dB map (SPL vs. Frequency) exportResultType=2 gives band filtered animation (Filtered pressure vs. Time).
fftnperseg (integer)
Number of segments (in frequency blocks) to consider for each window in the Fast Fourier Transformation Used for both type=surface and type=probe. Utilize fftnperseg=default to allow the number of available blocks to dictate the overlap size.
fftoverlap (integer)
Number of segments (in frequency blocks) to overlap between each window in the Fast Fourier Transformation. Used for both type=surface and type=probe. Utilize fftnoverlap=default to allow the number of available blocks to dictate the overlap size.
fftwinod (enum)
Window type used for Fast Fourier Transformation, accepts hanning, hamming, blackman.
colormap_name (enum)
Colormap name to use for displaying the scalar function values. Options: Cool to Warm, Cool to Warm (Extended), Black-Body Radiation, X Ray, Inferno, Black, Blue, and White, Blue Orange, Viridis, Gray and Red, Linear Green, Cold and Hot, Blue – Green – Orange, Rainbow Desaturated, Yellow – Gray – Blue, Rainbow Uniform, Rainbow, Rainbow Legacy.
view (string)
View to capture the image from. Note, only a single view is supported for GSP command, type=surface.

Example

The following example is given to demonstrate the use of the GSP command to compute the band filtered animation from the input file windshield.h3d, utilizing the full input time record from time=0.2991 – 1.1 sec. The frequency range of 1000 – 2000 Hz is set to restrict the filtering algorithm to report only those frequencies. The command will result in a BAFA written to ws_pass.mp4 with frames written at every 10 steps, using the “Cool to Warm (Extended)” colormap, viewed from the “front”.
GSP("BAFA Windshield Surface"){
	type                       =  surface
     resultFile                  = " windshield.h3d" 
	outGspFname                =  "windshield_out_pass.gsph5"
	partName                   =  "Glasses_windshield_pass"
	resultsName                =  "Glasses_windshield_pass"
     useCellData                =  true
	dataArrayName              =  pressure
     timeRange                  =  [0.29910001, 1.1]
     bandType                   =  "single_band"
     scale                      =  ""
     frequencyRange             =  [1000, 2000.0] 
     surfaceMapType             =  2
     exportData                 =  2 
     exportStride               =  10 
     exportDataFilename         =  "ws_pass"
     exportResultType           =  2
	fftnperseg                 =  4096
	fftnoverlap                =  default
	fftwindow                  =  hann
	background_color           = "white"
     colormap_name              = "Cool to Warm (Extended)"
     view                       =  "front"
}

GSP("dB Map Windshield Surface"){
	type                       =  surface
     resultFile                  = " windshield.h3d" 
	outGspFname                =  "windshield_out_pass.gsph5"
	partName                   =  "Glasses_windshield_pass"
	resultsName                =  "Glasses_windshield_pass"
     useCellData                =  true
	dataArrayName              =  pressure
     timeRange                  =  [0.29910001, 1.1]
     bandType                   =  "octave"
     scale                      =  ""
     frequencyRange             =  [20.0, 11251.486] 
     surfaceMapType             =  2
     exportData                 =  2 
     exportStride               =  1 
     exportDataFilename         =  "ws_pass"
     exportResultType           =  2
	fftnperseg                 =  4096
	fftnoverlap                =  default
	fftwindow                  =  hann
	background_color           = "white"
     colormap_name              = "Cool to Warm (Extended)"
     view                       =  "front"
}