Octave {Tools}

From personal use

• plotting
  • plot(X) with X being a vector of values
  • subplot(number_of_horizontal_plots,1,position)
• function return_value = my_function_name(var1, var2)
  • ...
  • endfunction
• from interactive prompt to file
  • simply exist Octave then transform ~/.octave_history to your script
    • load the resulting script with source my_script.m
  • see also diary
• X(2:end-1) : remove the first and last value of the vector
  • note that X(2:length(X)) works and X(2:size(X,1)) too but it might fail, e.g. using X'
• repmat : replicate matrix
• bsxfun : apply function between matrices of different sizes
  • for a clearer explanation see instead SciPy Broadcasting
  • syntax
    • current dev version, (x - mean(x))./(max(x) - min(x))
    • the current release, however (and in Matlab) bsxfun(@rdivide, bsxfun(@minus, x, mean(x)), max(x) - min(x))
  • see also arrayfun
• whos : shows the currently assigned variables
  • see also 'who giving only their names
• pinv : pseudo inverse
  • see also inv for the inverse
• up arrow : go back in command history
  • in then up arrow : go back in command history limited to commands starting with in e.g. inv(A)
• [1 0; 0 1] : example of matrix notation
  • X' : tranverse of matrix X
• help : the MOST important command ;)
  • e.g. help inv to get details on the function to get the inverse of a square matrix

From YetAnotherTutorial

• this does that
• this other command is nice

To explore

• links to websites with content to discover
• StructuralInformationAsymmetries#Tools
• WatchingNotes#MachineLearningCS229
• MLClass
• Wikipedia:GNU Octave

Note

My notes on Tools gather what I know or want to know. Consequently they are not and will never be complete references. For this, official manuals and online communities provide much better answers.