Table 2.

Examples of merging operations performed on multiple parcel-specific data arrays, for some JDE outputs: parcel-specific HRFs and condition- and voxel-specific activation labels.

	Parcel-specific flat data		Merging operation	Whole brain data
	Axis label	Axis domain		Axis label	Axis domain
HRF	Time	[0, …, hrf_duration]	=		same
			∪	Parcel	[0, …, parcel_max]
Labels	Class	[’activ’, ’non_activ’]	=		same
	Condition	[’audio, ’video’]	=		same
	Position	[0, …, pos_max]	→	Axial	[0, …, axial_max]
				Coronal	[0, …, coronal_max]
				Sagittal	[0, …, sagittal_max]

If the xndarray object contains the “position” axis, as for the “labels” object, then all parcel-specific results are merged into the same target volume and we depict the spatial mapping operation as “→” to map the “position” axis in to the spatial axes “axial,” “coronal,” and “sagittal.” For other axes aside from “position,” no merging operation is performed (“ = ” symbol). If the xndarray object does not contain the “position” axis, as for the HRF object, then all parcel-specific results are stacked and a new “parcel” axis is created (“∪” symbol).