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PeakLatency

Find the latency or offset of the tallest peak along an axis.

This node finds the largest element along an axis and outputs the offset/shift of that element along the axis (and if the data has other axes, e.g., channels, then for each channel/etc the offset is computed separately). One can optionally also find the smallest element (i.e., negative peak). The chosen axis will generally be replaced by a one-element feature axis. By default, the offset is returned as the index of the element, counting from zero for the first element. However, in the special case that the node is applied over the time axis, it is possible to measure the offset instead in seconds, and one may also look up the position in seconds from the time axis (e.g., relative to whatever is 0 in the time axis). One can also optionally account for the delay of previous filter nodes, to the extent that the data is annotated with it. Version 1.0.0

Ports/Properties

data

Data to process.

  • verbose name: Data
  • default value: None
  • port type: DataPort
  • value type: Packet (can be None)
  • data direction: INOUT

axis

Axis along which to find the peak. This axis will drop out of the data and be replaced by a one-element feature axis.

  • verbose name: Find Peak Along Axis
  • default value: time
  • port type: ComboPort
  • value type: str (can be None)

negative

Apply to negative peaks. If checked, the smallest element will be searched, instead of the largest.

  • verbose name: Find Negative Peaks
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

unit

Output unit, depending on axis that the peak is searched along. Using seconds here works only if the operation is performed along the time axis, and if the axis has a sampling rate set.

  • verbose name: Unit Of Measurement
  • default value: samples
  • port type: EnumPort
  • value type: str (can be None)

subtract_filter_delay

Subtract filter delay (time axis only). Note that this is most reliable when used with only linear-phase filters (e.g., FIR filter without minimum phase option), since otherwise the delay will depend on the frequency content of the signal.

  • verbose name: Subtract Filter Delay
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

account_for_time_axis

Look up latency from the time axis. If unchecked, the lantency will be computed relative to the beginning of the data segment, but if checked, it will be relative to whatever is 0.0 in the time axis (and would even work with irregularly sampled data).

  • verbose name: Account For Time Axis
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

update_on_streaming

Update on streaming data. If enabled (default), then this node will update its output measure on every chunk, whether it is marked as streaming or not. If False, then it will only update on non-streaming, chunks, such as calibration data.

  • verbose name: Update On Streaming Data
  • default value: True
  • port type: BoolPort
  • value type: bool (can be None)

set_breakpoint

Set a breakpoint on this node. If this is enabled, your debugger (if one is attached) will trigger a breakpoint.

  • verbose name: Set Breakpoint (Debug Only)
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

metadata

User-definable meta-data associated with the node. Usually reserved for technical purposes.

  • verbose name: Metadata
  • default value: {}
  • port type: DictPort
  • value type: dict (can be None)