newBlockwiseData: Create, merge and expand BlockwiseData objects

In nosarcasm/WGCNA: Weighted Correlation Network Analysis

Description

These functions create, merge and expand BlockwiseData objects for holding in-memory or disk-backed blockwise data. Blockwise here means that the data is too large to be loaded or processed in one piece and is therefore split into blocks that can be handled one by one in a divide-and-conquer manner.

Usage

newBlockwiseData(
   data, 
   external = FALSE, 
   fileNames = NULL, 
   doSave = external, 
   recordAttributes = TRUE, 
   metaData = list())

mergeBlockwiseData(...)

addBlockToBlockwiseData(
   bwData,
   blockData,
   external = bwData$external,
   blockFile = NULL,
   doSave = external,
   recordAttributes = !is.null(bwData$attributes),
   metaData = NULL)

Arguments

data	A list in which each component carries the data of a single block.
external	Logical: should the data be disk-backed (TRUE) or in-memory (FALSE)?
fileNames	When external is TRUE, this argument must be a character vector of the same length as data, giving the file names for the data to be saved to, or where the data is already located.
doSave	Logical: should data be saved? If this is FALSE, it is the user's responsibility to ensure the files supplied in fileNames already exist and contain the expected data.
recordAttributes	Logical: should attributes of the given data be recorded within the object?
metaData	A list giving any additional meta-data for data that should be attached to the object.
bwData	An existing BlockwiseData object.
blockData	A vector, matrix or array carrying the data of a single block.
blockFile	File name where data contained in blockData should be saved.
...	One or more objects of class BlockwiseData.

Details

Several functions in this package use the concept of blockwise, or "divide-and-conquer", analysis. The BlockwiseData class is meant to hold the blockwise data, or all necessary information about blockwise data that is saved in disk files.

The data can be stored in disk files (one file per block) or in-memory. In memory storage is provided so that same code can be used for both smaller (single-block) data where disk storage could slow down operations as well as larger data sets where disk storage and block by block analysis are necessary.

Value

All three functions return a list with the class set to "BlockwiseData", containing the following components:

external	Copy of the input argument external
data	If external is TRUE, an empty list, otherwise a copy of the input data.
fileNames	Copy of the input argument fileNames.
lengths	A vector of lengths (results of length) of elements of data.
attributes	If input recordAttributes is TRUE, a list with one component per block (component of data); each component is in turn a list of attributes of that component of data.
metaData	A copy of the input metaData.

Warning

The definition of BlockwiseData should be considered experimental and may change in the future.

Author(s)

Peter Langfelder

See Also

Other functions on BlockwiseData:

BD.getData for retrieving data

BD.actualFileNames for retrieving file names of files containing data;

BD.nBlocks for retrieving the number of blocks;

BD.blockLengths for retrieving block lengths;

BD.getMetaData for retrieving metadata;

BD.checkAndDeleteFiles for deleting files of an unneeded object.

nosarcasm/WGCNA documentation built on May 28, 2019, 1:01 p.m.