cuDFOnRay Dataframe Implementation

Modin implements Dataframe, PartitionManager, AxisPartition, Partition and GPUManager classes specific for cuDFOnRay execution:

• cuDFOnRayDataframe

• cuDFOnRayDataframePartition

• cuDFOnRayDataframeAxisPartition

• cuDFOnRayDataframePartitionManager

• GPUManager