> sum(a) % Adds all elements in a and returns (17.5). % Where: c = col, r = row of any value >= 7. > r,c = find(A>=7) % Finds the row, column index of all values >= 7.

> A = magic(3) % 3x3 matrix where all cols up to same value. % WARNING: if matrix does max for each column. > val = max % Returns (3) max value in v. > exp(v) % ' ' ' ' ' ' base e exponentiaion * B % element-wise multiplication (must be same dimensions) > A * C % matrix multiplication (results is 3x2 matrix) > v = % NOTE: commas behave same as semicolons you can write code in files ending with '.m' (example: myFunction.m) and call those files / functions so long as you are in that directory.' cd ls pwd' - these common unix commands work as you'd expect.' a=1,b=2,c=3' - comma chain commands.' ' - put this on the end of a line to suppress output, otherwise 'v = ' will show all 100 lines with.If you install Octave you can copy and paste these commands to see the full output from each line. Often I'll explain output in the % comments, but generally I have saved space by not showing any output lines. Here I go through some commands - roughly in the order I saw them in the online machine learning course.

It works on all platforms, although on windows you will need to install it with Cygwin. Octave is an excellent language to prototype machine learning. Most of them I actually saw in an excellent online machine learning course which is referenced and acknowledged properly below, and was my reason for learning Octave. This page is my own 'cheat sheet' where I list out most of the commands I'll need. The language is very similar to and *mostly* comaptible with MATLAB - but unlike Matlab is free and open source under a GNU General Public License. It provides its own command line interface for solving linear and nonlinear problems and plotting graphs. GNU Octave is a high-level programming language, primarily intended for numerical computations, and very useful for matrix operations.

Gnu octave plot