type TStatsBuffer = class(TSignal);
Abstract class for storing statistics computed from Input data.
The computation can be customized within an event or also with user specified math expression. Each computation returns one scalar value computed from the input vector.
The values computed are stored in the Data property. When the buffering is reset, the next value will again be written at Data[0]. When Data vector is full, the Update function returns pipeOK and no longer pipeStream. pipeOK is returned once, then the counters are reset again to start writing at Data[0].
The component usually connected to the Input of this component is TSignalBuffer. TSignalBuffer.StrideLength is automatically assigned to the StrideLength property in this case. StrideLength property defines the sampling frequency of the output data as: SamplingFrequency := Input.SamplingFrequency/StrideLength; StrideLength defines the step in number of samples between consecutive windows of data from which the statistical parameters are computed. The Length of the windows is specified with the Input.Length property.
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. |
| BandWidth | Double | Return the bandwidth of the signal. |
| 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". |
| ChannelCount | Integer | Get or set the number of channels multiplexed in the data property. |
| Complex | Boolean | Set this property to true, to request computation using complex numbers. |
| Continuous | Boolean | If True, the component will pass on the udpate request to the connected component. |
| Data | TVec | Stores the result of the processing. |
| Dt | Double | Time between two consecutive samples. |
| 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. |
| HzRes | Double | Frequency resolution obtained, if an FFT algorithm would be run on the data. |
| Input | TAnalysis | Connector property to obtain a pointer to the TSignal component holding the data to be processed. |
| IsDouble | Boolean | Set this property to false, to request computation in 32bit floating point precision, 64bit, if true. |
| Item | Double | Default property to access values of a real signal. |
| ItemNumber | Integer | Number to label the object when it is an item in the List. |
| Length | Integer | Get or set the length of the signal in samples. |
| Marks | TMarkList | Stores the time stamps and amplitude of selected samples. |
| MaxAmplt | Double | Stores the maximum amplitude of the signal found by the MinMax method. |
| MaxX | Double | Use the MaxX property to store the time stamp (in seconds) of the right most sample. |
| MinAmplt | Double | Stores the minimum amplitude of the signal found by the MinMax method. |
| MinX | Double | Use the MinX property to store the time stamp of the left-most sample. |
| OnAfterUpdate | TNotifyEvent | The event is triggered after the call to the Update method. |
| OnBeforeUpdate | TNotifyEvent | The event is triggered just before the call to the Update method. |
| OnBufferFilled | TNotifyEvent | Called when buffer is full and before the data contained is used by any conected components. |
| OnComputeStats | TOnComputeStats | To compute custom statistics, place the computation inside this event and assign the result to the result variable. |
| 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". |
| 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. |
| SamplingFrequency | Double | Defines the sampling frequency of the signal. |
| SamplingTime | Double | The length of the signal in seconds. |
| StrideLength | Integer | Specifies the number of samples the input buffer skips forward on each new buffer returned. |
| SuspendNotifyUpdate | Boolean | Set this property to True, to prevent calling OnNotifyUpdate from the Update Method. |
| UsesInputs | Boolean | Set it to True to indicate, that valid signals will be connected to the Input or Inputs properties. |
Methods
| Name | Description |
|---|---|
| AllowStreaming | Returns the negatated value of BlockAssign. |
| Append | Appends Sample to the end of the signal. |
| Assign | Assign values of all published properties from Source. |
| AssignTemplate | Assign values of "template-like" published properties from Source. |
| Copy | Copies signal Data and sampling frequency information. |
| Crest | Compute the CREST parameter. |
| CurrentCount | Returns the current position at which the values are written in the Data property. When the buffer is full it passes pipeOK to the connected component and rolls over. |
| EditorClass | To be overriden in descendanr classses. |
| InputsDirty | If all Inputs[i] are dirty the function returns true. |
| 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. |
| MarksToStrings | Convert marks to strings. |
| MinMax | Find minimum and maximum amplitude and store the result in the MinAmplt and MaxAmplt properties. |
| 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. |
| Peak | Find the maximum deviation of the signal from its mean value. |
| PipeReset | Recursively processes all connected components backward and calls Reset method. |
| Pull | Request recalculation of the entire chain of all connected components. |
| PullUntilEnd | Calls Pull until pipeEnd is returned. |
| Reset | Resets buffering. |
| SaveTemplateToFile | Save template to file. |
| SaveTemplateToStream | Save template to stream. |
| SaveToStream | Save the component to Dst stream. |
| Size | Assign the size of the signal from Src. |
| Update | Request recalculation of the data and place the result in Self. |
| UpdateNotify | Call this method only, if SuspendNotifyUpdate is True. |
| ValuesToStrings | Convert values to strings. |