TSpectrogram Class — DSP Master

type TSpectrogram = class(TStaticSpectrumAnalyzer);

Form vectors from a list of TMarkList's.

Spectrogram expects a TSpectrumAnalyzer or descendant to be connected to its Input property. Each time the Pull method is called on component, the connected components are recalcuated and new spectrum is added to the list of spectrums within the component. There are various support routines avialable to help manage that data. Typical usage scenarios are like this (assuming single channel file):

SignalRead.FileName := YourFile;
SignalRead.OpenFile;
SignalRead.RecordTimePosition := StartingTime;
SpectrumAnalyzer.Input := SignalRead;
Spectrogram.Input := SpectrumAnalyzer;
Spectrogram.PullUntilEnd;//process entire file

Spectrogram.SpectralTimeOffset := StartingTime;
Spectrogram.SpectralSamplingFrequency := 1/SignalRead.FramesPerSecond;

Alternative:

        SignalRead.FileName := YourFile;
        SignalRead.OpenFile;
        SignalRead.RecordTimePosition := StartingTime;
        SpectrumAnalyzer.Input := SignalRead;
        SpectrumAnalyzer.Peaks.TraceMethod := ptAmpltHarmonics;

        Spectrogram.TraceOnly := true;
        Spectrogram.Input := SpectrumAnalyzer;
        Spectrogram.PullUntilEnd;//process entire file

        Spectrogram.Trace.EndTrace;
        Spectrogram.Trace.SpectralTimeOffset := StartingTime;
        Spectrogram.Trace.SpectralSamplingFrequency := 1/SignalRead.FramesPerSecond;

//        Spectrogram.Trace[i].Freq  //TVec contains gathered data
//        Spectrogram.Trace[i].Amplt //TVec contains gathered data

Examples

delphi

SignalRead.FileName := YourFile;
SignalRead.OpenFile;
SignalRead.RecordTimePosition := StartingTime;
SpectrumAnalyzer.Input := SignalRead;
Spectrogram.Input := SpectrumAnalyzer;
Spectrogram.PullUntilEnd;//process entire file

Spectrogram.SpectralTimeOffset := StartingTime;
Spectrogram.SpectralSamplingFrequency := 1/SignalRead.FramesPerSecond;

Properties

Name	Type	Description
Active	Boolean	Set active to false to suppress the propagation of the Pull request and the subsequent call to the Update method.
Amplt	TVec	Stores the amplitude of the spectrum.
Averages	Integer	Used to store the number of averages made.
Bands	TSpectrumBandsAnalyzer	Holds the parameters for the frequency bands.
BandWidth	Double	Returns the bandwidth of the spectrum in [Hz].
BandwidthH	Double	Returns the upper bandwidth edge of the signal.
BandwidthL	Double	Returns the lower bandwidth edge of the signal.
BlockAssign	Boolean	Block streaming of specific properties when storing only a "template".
Complex	Boolean	Set this property to true, to request computation using complex numbers.
ConjExtend	Boolean	If True, the conjugate symmetric part of the frequency spectrum is to be computed.
ConjFlip	Boolean	If True, the conjugate symmetric part of the frequency spectrum will be placed in 0.5..1.0 Fs (as returned by the FFT), and not between -0.5..0.0 Fs.
Continuous	Boolean	If True, the component will pass on the udpate request to the connected component.
Count	Integer	Specifies the number of the spectrums in the list.
Dt	Double	Returns the distance in seconds between two consecutive samples of the signal on which the frequency spectrum is based.
EditorActive	Boolean	Returns True, if the component editor is displayed.
FloatPrecision	TMtxFloatPrecision	Set this property to request computation in 32bit/64bit precision with real/complex numbers.
FloatPrecisionLock	Boolean	Set this property to true to lock changes to FloatPrecision property.
Harmonics	Integer	Defines number of harmonics to be used when calculating statistical parameters from the amplitude spectrum.
HzRes	Double	Returns the frequency resolution in Hz.
Input	TSpectrum	Specifies Input for the data to the component.
IsDouble	Boolean	Set this property to false, to request computation in 32bit floating point precision, 64bit, if true.
IsSpectrumAnalyzer	Boolean	Returns true, if the descendant class is derived from TSpectrumAnalyzer.
Item	TStaticSpectrumAnalyzer	Returns spectrum at index i.
ItemNumber	Integer	Number to label the object when it is an item in the List.
Length	Integer	Defines the length of the spectrum.
Logarithmic	Boolean	If true, the stored spectrums will be converted to Logarithmic scale.
LogSpan	TLogSpan	Defines the span of the logarithmic spectrum in dB.
MainlobeWidth	Integer	Defines the width of the main lobe. Each frequency component in the frequency spectrum should theoretically be infinitely thin.
Marks	TMarkList	Stores the frequency, amplitude and phase of selected frequency bins.
MaxAmplt	Double	Stores the maximum value of the Amplt spectrum found by the MinMaxAmplt method.
MaxFreqIndex	Integer	Holds the index at which the maximum amplitude was found by the MinMaxAmplt method.
MaxPhase	Double	Stores the maximum value of the Phase spectrum found by the MinMaxPhase method.
MaxSpectrumCount	Integer	Maximum number of spectrums up to which the spectrogram will grow.
MinAmplt	Double	Stores the minimum value of the Amplt spectrum found by the MinMaxAmplt method.
MinPhase	Double	Stores the minimum value of the Phase spectrum found by the MinMaxPhase method.
NarrowBandH	Double	Specify value other than 0 to indicate the final frequency of the reduce bandwidth.
NarrowBandL	Double	Specify value other than 0 to indicate the start of the reduced bandwidth.
OnAfterUpdate	TNotifyEvent	The event is triggered after the call to the Update method.
OnBandsUpdate	TNotifyEvent	If assigned, this event will be called instead of a call to Bands.Update method.
OnBeforeUpdate	TNotifyEvent	The event is triggered just before the call to the Update method.
OnDisplayUpdate	TNotifyEvent	The event is triggered after the OnAfterUpdate event. Use this event to update any associated charts or graphs or result tables.
OnGetInput	TNotifyEvent	If the Input property is not assigned, the component will call OnGetInput.
OnNotifyUpdate	TNotifyEvent	The event is called after a call to InternalUpdate, OnAfterUpdate and OnDisplayUpdate from within the Update method.
OnParameterUpdate	TNotifyEvent	The event is triggered when ParamUpdate method is called. The ParamUpdate method is usually called by component editors when a value was changed by the user and the editor was "Live".
OnPeaksUpdate	TNotifyEvent	If assigned, this event will be called instead of a call to Peaks.Update method.
Peaks	TSpectrumPeaksAnalyzer	Pointer to the component that manages peak analysis.
Phase	TVec	Stores the phase of the spectrum.
PhaseMode	TPhaseMode	This property determines how to handle the phase of the frequency spectrum.
PhaseRange	TPhaseRange	Specify the range of the phase spectrum.
PhaseUnits	TPhaseUnits	Defines the units of phase. (radian, degrees).
PipeState	TPipeState	Returns the state of the pipe after the last update.
Reference	TReferenceList	Stores a list of components that have to be notified, when this component is destroyed.
Report	TSpectrumReport	Holds the parameters needed to generate a spectrum analysis report. Requires that the descriptor property is properly filled up.
SamplingFrequency	Double	Defines the sampling frequency of the signal on which the frequency spectrum is based.
SamplingTime	Double	Defines the length of the signal on which the frequency spectrum is based in seconds.
SpectralDt	Double	Time in seconds between consecutive spectrums.
SpectralSamplingFrequency	Double	Sampling frequency with which the spectrums are being sampled. When setting this property Dt is automatically updated.
SpectralSamplingTime	Double	Total length in seconds between the first and the last spectrum.
SpectralTimeOffset	Double	Time in seconds at which the spectrogram starts.
SuspendNotifyUpdate	Boolean	Set this property to True, to prevent calling OnNotifyUpdate from the Update Method.
Trace	TTraceList	Containes parameters and results for individual traces.
TraceOnly	Boolean	Specifies to track only marked peaks without entire spectrums.
UsesInputs	Boolean	Set it to True to indicate, that valid signals will be connected to the Input or Inputs properties.
ZeroPadding	Integer	Defines the level of zero padding of the source signal.

Methods

Name	Description
Add	Add amplitude and phase of the ASpectrum to the current spectrum.
AllowStreaming	Returns the negatated value of BlockAssign.
AmpltEst (4)	Returns the amplitudes of the frequency spectrum at Freq frequencies.
AmpltSpectrum	Compute amplitude spectrum from X.
Assign	Assign values of all published properties from Source.
AssignTemplate	Assign values of "template-like" published properties from Source.
BandFlip	Flip the frequency spectrum on the frequency axis.
ConvergeToMaximum (2)	Searches for the closest peaks of the amplitude spectrum.
Copy	Copy ASpectrum to the calling spectrum.
CopyAmplt	Copies all amplitude spectrums as rows to the destination matrix.
CopyAmpltTransposed (2)	Copies all amplitude spectrums as columns to the destination matrix.
CopyPhase	Copies all phase spectrums as rows to the destination matrix.
Delete	Delete the spectrum at index i.
Differentiate	Differentiate the underlying signal in the frequency domain by scaling each amplitude line with a power of its angular frequency.
Divide	Divide the calling the spectrum with ASpectrum.
EditorClass	To be overriden in descendanr classses.
FetchTraces	Copies marked values from spectrogram to the Trace property.
FilterPeak	Filter the peak at Marks position Index from the signal and recalculate the spectrum.
FreqToFreqIndex	Computes range checked array indexes in the spectrum from frequency values.
InputsDirty	If all Inputs[i] are dirty the function returns true.
Insert	Insert spectrum at index.
Integrate	Integrate the underlying signal in the frequency domain by dividing each amplitude line by a power of its angular frequency, restoring the DC term afterwards.
InternalPull	When called, the method will pass Update requests recursively to all connected objects.
Invalidate	Notifies all connected components that this component has fresh data.
LoadFromStream	Load the component from Src stream.
LoadTemplateFromFile	Load a template from file.
LoadTemplateFromStream	Load a template from stream.
LogAmplt	Compute the logarithm of the amplitude spectrum and convert to dB.
MarksToStrings	Convert marks to strings.
MinMax	Calls MinMaxAmplt and MinMaxPhase.
MinMaxAmplt	Find minimum and maximum value of the Amplt spectrum.
MinMaxPhase	Find minimum and maximum value of the Phase spectrum.
Move	Move spectrum from SrcIdx to DstIdx index.
Mul	Multiply the calling the spectrum with ASpectrum.
NF	Noise floor in dB: the mean absolute noise line (lines outside the mark guard bands), relative to the largest marked peak.
ParamUpdate	The method can be assigned to some other component even handler, as a notification that a parameter has changed and that Self should consider a recalculation.
PeakApproximate	Return the peak closest to the Freq frequency.
PhaseEst (4)	Returns the phases of the frequency spectrum at Freq frequencies.
PhaseSpectrum	Compute phase spectrum from X.
PipeReset	Recursively processes all connected components backward and calls Reset method.
PowerSpectrum	Compute power spectrum from X.
Pull	Request recalculation of the entire chain of all connected components.
PullUntilEnd	Calls Pull until pipeEnd is returned.
Reset	Reset the spectrogram and delete the stored data.
RMS	Root-mean-square value reconstructed from the amplitude spectrum.
RMSSpectrum	Compute RMS spectrum from X.
Rotate	Rotate spectrums down or up in the list.
SaveTemplateToFile	Save template to file.
SaveTemplateToStream	Save template to stream.
SaveToStream	Save the component to Dst stream.
Scale	Scale the calling spectrum with Factor.
SetZero	Initialize spectrum to zero.
SFDR	Spurious-free dynamic range in dB: the ratio of the largest marked peak to the second-largest marked peak.
SINAD	Signal-to-noise-and-distortion ratio in dB. Compares the largest marked peak against the noise floor plus every other marked peak.
Size	Assign Length, Complex and SamplingFrequency properties.
SNR	Signal-to-noise ratio in dB. Sums the absolute amplitudes of all marked peaks and compares against the sum of the absolute amplitude lines outside the mark guard bands.
Sqr	Square the Amplt and Phase of the ASpectrum and copy it to self.
Subtract	Subtract ASpectrum from the calling spectrum.
THD	Total harmonic distortion in percent. Returns the RMS of the marked harmonic peaks (all marks after the first, when sorted by frequency, up to Harmonics) relative to the first (fundamental) marked peak.
THDN	Total harmonic distortion plus noise, in percent. Combines the noise floor power with the power of every marked peak except the largest, relative to the largest marked peak.
Update	Request recalculation of the data and place the result in Self.
UpdateAllTraces	Updates marks for all spectrums then calls FetchTraces.
UpdateNotify	Call this method only, if SuspendNotifyUpdate is True.
UpdateTraceParameters	Propagates settings of Peaks and Bands properties to all spectrums.
ValuesToStrings	Convert values to strings.