summary.hdd: Summary information for HDD objects

In hdd: Easy Manipulation of Out of Memory Data Sets

Summary information for HDD objects

Description

Provides summary information – i.e. dimension, size on disk, path, number of slices – of hard drive data sets (HDD).

Usage

## S3 method for class 'hdd'
summary(object, ...)

Arguments

object	A HDD object.
...	Not currently used.

Details

Displays concisely general information on the HDD object: its size on disk, the number of files it is made of, its location on disk and the number of rows and columns.

Note that each HDD object contain the text file “_hdd.txt” in their folder also containing this information.

To obtain how the HDD object was constructed, use function origin.

Value

This function does not return anything. It only prints general information on the data set in the console.

Author(s)

Laurent Berge

See Also

See hdd, sub-.hdd and cash-.hdd for the extraction and manipulation of out of memory data. For importation of HDD data sets from text files: see txt2hdd.

See hdd_slice to apply functions to chunks of data (and create HDD objects) and hdd_merge to merge large files.

To create/reshape HDD objects from memory or from other HDD objects, see write_hdd.

To display general information from HDD objects: origin, summary.hdd, print.hdd, dim.hdd and names.hdd.

Examples

# Toy example with iris data
iris_path = tempfile()
fwrite(iris, iris_path)

# destination path
hdd_path = tempfile()

# reading the text file with 50 rows chunks:
txt2hdd(iris_path, dirDest = hdd_path, rowsPerChunk = 50)

# creating a HDD object
base_hdd = hdd(hdd_path)

# Summary information on the whole data set
summary(base_hdd)

# Looking at it like a regular data.frame
print(base_hdd)
dim(base_hdd)
names(base_hdd)

hdd documentation built on Aug. 25, 2023, 5:19 p.m.