bids.variables.entities.NodeIndex¶
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class
NodeIndex
[source]¶ Represents the top level in a BIDS hierarchy.
Methods
add_variable
(self, variable)Adds a BIDSVariable to the current Node’s list.
create_node
(self, level, entities, \*args, …)Creates a new child Node.
get_collections
(self, unit[, names, merge, …])Retrieve variable data for a specified level in the Dataset.
get_nodes
(self[, level, entities, strict])Retrieves all nodes that match the specified criteria.
get_or_create_node
(self, level, entities, …)Retrieves a child Node based on the specified criteria, creating a new Node if necessary.
Methods
__init__
(self)Initialize self.
add_variable
(self, variable)Adds a BIDSVariable to the current Node’s list.
create_node
(self, level, entities, \*args, …)Creates a new child Node.
get_collections
(self, unit[, names, merge, …])Retrieve variable data for a specified level in the Dataset.
get_nodes
(self[, level, entities, strict])Retrieves all nodes that match the specified criteria.
get_or_create_node
(self, level, entities, …)Retrieves a child Node based on the specified criteria, creating a new Node if necessary.
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add_variable
(self, variable)¶ Adds a BIDSVariable to the current Node’s list.
- Parameters
variable (BIDSVariable) – The Variable to add to the list.
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create_node
(self, level, entities, *args, **kwargs)[source]¶ Creates a new child Node.
- Parameters
level (str) – The level of analysis of the new Node.
entities (dict) – Dictionary of entities belonging to Node
kwargs (args,) – Optional positional or named arguments to pass onto class-specific initializers. These arguments are only used if a Node that matches the passed entities doesn’t already exist, and a new one must be created.
- Returns
A Node instance.
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get_collections
(self, unit, names=None, merge=False, sampling_rate=None, **entities)[source]¶ Retrieve variable data for a specified level in the Dataset.
- Parameters
unit (str) – The unit of analysis to return variables for. Must be one of ‘run’, ‘session’, ‘subject’, or ‘dataset’.
names (list) – Optional list of variables names to return. If None, all available variables are returned.
merge (bool) – If True, variables are merged across all observations of the current unit. E.g., if unit=’subject’ and return_type= ‘collection’, variablesfrom all subjects will be merged into a single collection. If False, each observation is handled separately, and the result is returned as a list.
sampling_rate (int, str) – If unit=’run’, the sampling rate to pass onto the returned BIDSRunVariableCollection.
entities – Optional constraints used to limit what gets returned.
- Returns
A list of BIDSVariableCollections if merge=False; a single BIDSVariableCollection if merge=True.
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get_nodes
(self, level=None, entities=None, strict=False)[source]¶ Retrieves all nodes that match the specified criteria.
- Parameters
level (str) – The level of analysis of nodes to return.
entities (dict) – Entities to filter on. All nodes must have matching values on all defined keys to be included.
strict (bool) – If True, an exception will be raised if the entities dict contains any keys that aren’t contained in the current index.
- Returns
A list of Node instances.
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get_or_create_node
(self, level, entities, *args, **kwargs)[source]¶ Retrieves a child Node based on the specified criteria, creating a new Node if necessary.
- Parameters
level (str) – The level of analysis of the Node.
entities (dict) – Dictionary of entities to include in newly-created Nodes or filter existing ones.
kwargs (args,) – Optional positional or named arguments to pass onto class-specific initializers. These arguments are only used if a Node that matches the passed entities doesn’t already exist, and a new one must be created.
- Returns
A Node instance.
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