Octave Cheatsheet

Working with files

Load CSV file into a matrix. This command loads file ex2data.txt and stores its contents in a variable named ex2data:

load ex2data1.txt

Matrices and Vectors

Appending to a vector (does not work on matrices as this would break the rectangular shape):

a = [1; 2; 3];
a(end + 1) = 4;


Create empty figure:


Plot XY diagram using “+” markers in black:

plot(X, Y, "k+");

Plot multiple datasets in one XY diagram:

hold on
plot(X,Y,"k+") % draw with '+' markers
plot(A,B,"ko") % draw with 'o' markers
hold off % release figure


Create a random permutation of the integers 1 to 10:

v = randperm(10); % produces a row vector of size 1x10

The same function can be used for drawing without replacement, e.g., out of a number of items 1,2,…,10 take five distinct elements:

v = randperm(10, 5); % produces a row vector of size 5

Utility functions

Change default prompt (PS1):

PS1('>> ')

Change/check working directory:

pwd; %print working directory
cd '/tmp'; % change working directory to /tmp

What variables are currently defined/visible:

who; % short
whos; %long

Continue command in next line by typing three dots


Reading user input from the shell:

x = input(“Please enter the value of x: “);


  • Commands can be concatenated with a comma (produce output) or semicolon (hide output).
  • Reverse i search works just like for the Bash


  • [1] Octave documentation

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