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InterpolateMissingChannels

Interpolate missing channels in the given data.

Given a list of desired channel labels, this node will attempt to produce an output signal that has all channels in that list, and will interpolate channels that are not present in the data if needed. This node can use spherical-spline or least-squares interpolation. More Info... Version 1.5.1

Ports/Properties

data

Data to process.

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

ref_data

Reference data. Can be provided as an alternative to the desired_channels.

verbose name
Ref Data
default value
None
port type
DataPort
value type
Packet (can be None)
data direction
IN

prior_cov

Prior covariance matrix.

verbose name
Prior Cov
default value
None
port type
DataPort
value type
Packet (can be None)
data direction
IN

desired_channels

Desired channels. This node will attempt to ensure that the given channels are present in the output data and interpolate them if necessary. Ignored if ref_data provided.

verbose name
Desired Channels
default value
None
port type
ListPort
value type
list (can be None)

reinterpolate_existing

Whether to reinterpolate channels even if the desired label is already in the current channel list. This can be used to force a reinterpolation of existing channels at locations in a specific template.

verbose name
Reinterpolate Existing
default value
False
port type
BoolPort
value type
bool (can be None)

montage_type

Choose the montage to use from among a list of common options. If set to auto, the best-matching montage will be used.

verbose name
Montage Type
default value
auto
port type
EnumPort
value type
str (can be None)

montage

Optionally a montage file (.l ocs format) to use. This may be a montage file that ships with Neuropype (available in resources/montages), in which case only the filename is needed, or the full path to a montage located elsewhere. If specified, this will take precedence over the montage type field.

verbose name
Montage File
default value
port type
StringPort
value type
str (can be None)

additive_noise_scale

Scale of additive noise. Optional scale factor for Gaussian noise that can be added to each interpolated channel to prevent rank deficiency. Scale is relative to the overall data's standard deviation (assuming that channels are zero mean).

verbose name
Additive Noise Scale
default value
0
port type
FloatPort
value type
float (can be None)

mode

Interpolation mode. The spherical-spline mode will interpolate the channel based on its scalp location using spherical spline interpolation. The other two modes, which require that the prior_cov input is provided, will interpolate the channel using a statistical criterion based on a priori between-channel covariance. The lstsq method uses a least-squares solution, and the pinv method uses the pseudoinverse. The former is in theory more accurate but may leave exact zero channels in the data with greater likelihood than the pinv method.

verbose name
Mode
default value
spherical-spline
port type
EnumPort
value type
str (can be None)

backend

Compute backend to use. The cupy and torch backends can be as much as 10x faster on large problems if the system has a CUDA-capable GPU installed. For CPU-only systems, the torch-cpu mode can still yield a substantial speed boost over numpy. Keep means to use whatever was used to create the incoming data.

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). Only needed for the largest of problems, and only used by the geometric and huber centroids.

verbose name
Precision
default value
keep
port type
EnumPort
value type
str (can be None)

min_ev

Minimum eigenvalue threshold. If left undefined, this will be set according to the precision. If negative, then the absolute value of negative eigenvalues will be used.

verbose name
Min Ev
default value
None
port type
FloatPort
value type
float (can be None)

randseed

Random seed to use for interpolation.

verbose name
Randseed
default value
12345
port type
IntPort
value type
int (can be None)

verbose

Show verbose output.

verbose name
Verbose
default value
False
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)