`readtable`

Reads a delimited text or spreadsheet file into a table.

Category: Language Fundamentals > Data Types

Syntax

T = readtable(filename)

Reads the file, taking variable names from the first row and detecting the type of each column.

T = readtable(filename, opts)

Reads using an import options object.

T = readtable(___, Name, Value)

Adjusts reading with options such as 'Range' or 'VariableNamingRule'.

Description

readtable is the usual way to bring tabular data into the workspace. Column names come from the header line; characters that are not valid in a variable name are replaced (a name such as a;b becomes a_b) unless the naming rule is 'preserve'.

For control over types, missing-value markers or which columns to read, build an options object with detectImportOptions, change it with setvartype and setvaropts, and pass it as the second argument.

Input arguments

filename: Name of a .csv, .txt, .dat or spreadsheet file.
opts: Import options, for example from detectImportOptions.
'Range': Cell range to read, such as 'A2:B3'.

Output arguments

T: Table with one variable per column. Numeric columns become double, text columns become cell arrays of character vectors.

Example

fid = fopen('data.csv', 'w');
fprintf(fid, 'x,y\n1,a\n2,b\n');
fclose(fid);
T = readtable('data.csv')

Output

T = 2×2 table

    x      y  
    _    _____

    1    {'a'}
    2    {'b'}

The example first writes a small file in the current folder.

Notes

In MatLivre strings that look like dates stay as text instead of becoming datetime; convert them afterwards with datetime.

Only comma-separated text is split into columns. A file separated by semicolons, tabs or spaces is read as a single column, and the 'Delimiter' option has no effect, so convert such files to commas first.

readtable