Reading text files (readtable, textscan) in MATLAB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the readtable function do in MATLAB?

readtable reads data from a text file and stores it in a table format, making it easy to work with columns and rows.

intermediate

How does textscan differ from readtable?

textscan reads formatted data from a text file into cell arrays, giving more control over how each piece of data is read, but requires specifying the format.

beginner

What is the purpose of the format specifier in textscan?

The format specifier tells textscan how to interpret each piece of data in the file, like reading numbers, strings, or skipping parts.

intermediate

How can you skip the header line when using readtable?

You can use the option 'HeaderLines', 1 or specify 'ReadVariableNames', false to skip or ignore headers.

beginner

What type of output does textscan return?

textscan returns a cell array where each cell contains data from one column of the file, allowing flexible data types.

Which MATLAB function reads a text file directly into a table?

A readtable

B textscan

C fopen

D fprintf

readtable reads text files into tables directly, while textscan reads into cell arrays.

What does the format specifier '%f' mean in textscan?

A Read a string

B Skip a field

C Read a floating-point number

D Read an integer

The '%f' specifier reads floating-point numbers in textscan.

How do you open a file for reading in MATLAB before using textscan?

A fclose(filename)

B readtable(filename)

C textscan(filename)

D fopen(filename, 'r')

You use fopen with mode 'r' to open a file for reading before textscan.

What does textscan return after reading a file?

A A cell array

B A table

C A string

D A numeric matrix

textscan returns a cell array with each cell holding one column of data.

Which option skips the first line (header) when using readtable?

A 'HeaderLines', 1

B 'ReadVariableNames', true

C 'Format', '%s %f'

D 'Delimiter', ','

The option 'ReadVariableNames', false skips the first line (header) in readtable. The option 'HeaderLines', 1 is not valid for readtable.

Explain how to read a CSV text file into MATLAB using readtable and how to handle headers.

Think about how tables organize data and how headers can be included or skipped.

Describe the steps to read a text file with mixed data types using textscan.

Remember that textscan needs a format and returns cells.