Retrieving data from imported files

Before using Engee I/O functions, it is recommended to study the article Data import.

I/O functions are used to retrieve data from imported files:

Table of I/O functions
Purpose	Function	Description
Open	open	opens a file or data stream
Open	isopen	determines whether the object (stream or timer) is already closed or not.
Close	close	closes an I/O stream
	closeall	closes all open GUI windows
	closeeread	closes only the read-from-file thread associated with the I/O object
	closewrite	stops writing half of a full-duplex stream
Write	write	writes a canonical binary file representation of a value to the specified I/O stream or file
Write	iswritable	checks if writing to the specified object is supported
Read	read	reads the contents of a file
	read!	reads binary data from an I/O stream or file, filling the data matrix.
	readavailable	reads available buffered data from a stream
	readbytes!	performs a read of at most nb bytes from stream to b, returning the number of bytes to be read
	readchomp	reads the entire file as a string and removes one line break character at the end (if any).
	readdir	returns names in the directory (dir) or the current working directory if not specified.
	readeach	returns an iterated object resulting in read(io, T)
	readline	reads a single line of text from a given I/O stream or file.
	readlines	reads all lines in an IO stream or file as vector or string values
	readlink	returns the target location pointed to by a path symbolic link
	readuntil	reads a line from an I/O stream or file (up to the specified delimiter character).

To extend the I/O capabilities of specific formats, use the appropriate Julia packages (for more information on installing them, see here). For example, the difference in working with a CSV file with CSV.jl package and without the package is shown in the table below:

User action	C CSV.jl	Without CSV.jl
Installing	Installing the package: `Pkg.add("CSV.jl")` Using the package in code: `using CSV`	No third-party package installation required
Reading data	`output = CSV.read("file.csv")`	`output = read("file.csv", String)`
Convert	No additional conversion required.	Convert .csv data to an array of strings: `lines = split(output, "\n")` Converting CSV lines to arrays of values: `values = [split(line, ",") for line in lines]`
Additional	Ability to configure read and write parameters.	Requires additional data processing to obtain data structure.

User action

C CSV.jl

Without CSV.jl

Installing

Installing the package: Pkg.add("CSV.jl")

Using the package in code: using CSV

No third-party package installation required

Reading data

output = CSV.read("file.csv")

output = read("file.csv", String)

Convert

No additional conversion required.

Convert .csv data to an array of strings: lines = split(output, "\n")

Converting CSV lines to arrays of values: values = [split(line, ",") for line in lines]

Additional

Ability to configure read and write parameters.

Requires additional data processing to obtain data structure.

To work with popular formats we recommend to use the following Julia packages:

Retrieving data from imported files

Useful links