Fourier Analysis

genalyzer.fft_analysis(test_key, a, nfft, axis_type=FreqAxisType.DC_LEFT)

Returns all Fourier analysis results

Args:

test_key (string) : Key value to the Fourier Analysis object created (through gn_fa_create)

a (ndarray) : FFT data of type ‘complex128’ or ‘float64’

nfft (int) : FFT size

axis_type (FreqAxisType) : Frequency axis type

Returns:

results (dict) : Dictionary containing all Fourier analysis results

Notes:

Every Key:Value pair in the dictionary is str:float.

The dictionary contains the following keys:

signaltype : Signal type: 0=Real, 1=Complex

nfft : FFT size

datasize : Data size

fbin : Frequency bin size (Hz)

fdata : Data rate (S/s)

fsample : Sample rate (S/s)

fshift : Shift frequency (Hz)

fsnr : Full-scale-to-noise ratio (a.k.a. “SNRFS”) (dB)

snr : Signal-to-noise ratio (dB)

sinad : Signal-to-noise-and-distortion ratio (dB)

sfdr : Spurious-free dynamic range (dB)

abn : Average bin noise (dBFS)

nsd : Noise spectral density (dBFS/Hz)

carrierindex : Order index of the Carrier tone

maxspurindex : Order index of the MaxSpur tone

ab_width : Analysis band width (Hz)

ab_i1 : Analysis band first index

ab_i2 : Analysis band last index

{PREFIX}_nbins : Number of bins associated with PREFIX

{PREFIX}_rss : Root-sum-square associated with PREFIX

{TONEKEY}:ffinal : Tone final frequency (Hz)

{TONEKEY}:freq : Tone frequency (Hz)

{TONEKEY}:fwavg : Tone weighted-average frequency (Hz)

{TONEKEY}:i1 : Tone first index

{TONEKEY}:i2 : Tone last index

{TONEKEY}:inband : 1: tone is in-band; 0: tone is out-of-band

{TONEKEY}:mag : Tone magnitude

{TONEKEY}:mag_dbc : Tone magnitude relative to carrier (dBc)

{TONEKEY}:mag_dbfs : Tone magnitude relative to full-scale (dBFS)

{TONEKEY}:nbins : Tone number of bins

{TONEKEY}:orderindex : Tone order index

{TONEKEY}:phase : Tone phase (rad)

{TONEKEY}:phase_c : Tone phase relative to carrier (rad)

{TONEKEY}:tag : Tone tag