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ZScoring

Produce z-scored data, that is, data with a mean of zero and a variance of one.

The resulting data can be interpreted to be scores in units of standard deviations (Z units), relative to the sample mean. Note that, if your data is segmented or otherwise comes in the form of multiple instances, you can decide whether the statistics should be taken over the instances or over the time axis in each instance. You also can decide whether the statistics should be updated on every chunk, or if it should only be updated on the calibration data (non-streaming chunks), and whether they should be recomputed on subsequent non-streaming chunks (e.g., subsequent test data). Note that there is also a moving-window standardization node available. More Info... Version 1.2.0

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 over which the statistic should be aggregated. For instance, if this is set to time, then the mean/standard deviation will be computed over time.

  • verbose name: Take Statistics Along Axis
  • default value: instance
  • port type: ComboPort
  • value type: str (can be None)

pop_correction

Use Bessel's correction for the population standard deviation. If True, the standard deviation will be scaled by 1/(N-1), which yields a less biased estimate of the standard deviation of the (infinite) population from which the sample is assumed to be drawn, while if False, it will be scaled by 1/N, which yields the maximum-likelihood standard deviation estimate for the (finite) sample. Note that this is not applicable (and therefore ignored) in the robust mode, where the median absolute deviation is used instead of the standard deviation.

  • verbose name: Use Population Estimate
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

robust

Use robust estimators (median and median absolute deviation). Enabling this will make the node more robust to outlier elements, but if the data is clean, then the statistic will be somewhat less precise than it it could be.

  • verbose name: Use Robust Estimator
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

adapt_on_streaming

Adapt state parameters on streaming chunks. If this is False (the default), then this node will not adapt itself on streaming chunks, i.e., only on non-streaming chunks, such as imported calibration recordings. This is useful if the streaming chunks would be too short to meaningfully adapt the parameters on and the calibration recording is sufficietly similar to the streaming data for it to be meaningful to adapt the state only on these data. Or if set to True, the node will simply adapt itself on every chunk it receives, whether it is streaming or not.

  • verbose name: Adapt On Streaming Chunks
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

constrain

Optionally constrain data to have the same scale across one or more axes. Multiple axes can be given as a comma-separated list. If 2 axes are given, rank-1 offset and scale matrices are estimated using SVD and NMF, respectively.

  • verbose name: Constrain
  • default value:
  • port type: ComboPort
  • value type: str (can be None)

initialize_once

Initialize (adapt state parameters) only once. If False, this node will recalibrate itself on any qualifying chunk (based on the setting of adapt on streaming chunks).

  • verbose name: Adapt Only Once
  • default value: True
  • port type: BoolPort
  • value type: bool (can be None)

ignore_resets

Ignore signal resets.

  • verbose name: Ignore Resets
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

ignore_nans

If activated the data containing nan values are ignored.

  • verbose name: Ignore Channels With Nan Values
  • default value: False
  • port type: BoolPort
  • value type: bool (can be None)

epsilon

Optional epsilon value to prevent div by 0.

  • verbose name: Epsilon
  • default value: 0
  • port type: FloatPort
  • value type: float (can be None)

partition_size

Partition size. Optionally a size of chunks into which data shall be partitioned to conserve memory (if robust=True). This is done along the last axis of the data that isn't the axis of interest. This is a rarely used feature.

  • verbose name: Partition Size
  • default value: None
  • port type: IntPort
  • value type: int (can be None)

backend

Compute backend to use.

  • verbose name: Backend
  • default value: keep
  • port type: EnumPort
  • value type: str (can be None)

precision

Numeric precision to use. Can be reduced to save memory (e.g. if running on GPU).

  • verbose name: Precision
  • default value: keep
  • port type: EnumPort
  • value type: str (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)