Basic Operations

%% Change Octave prompt  
PS1('>> ');
%% Change working directory in windows example:
cd 'c:/path/to/desired/directory name'
%% Note that it uses normal slashes and does not use escape characters for the empty spaces.

%% elementary operations
5+6
3-2
5*8
1/2
2^6
1 == 2 % false
1 ~= 2 % true.  note, not "!="
1 && 0
1 || 0
xor(1,0)


%% variable assignment
a = 3; % semicolon suppresses output
b = 'hi';
c = 3>=1;

% Displaying them:
a = pi
disp(a)
disp(sprintf('2 decimals: %0.2f', a))
disp(sprintf('6 decimals: %0.6f', a))
format long
a
format short
a


%%  vectors and matrices
A = [1 2; 3 4; 5 6]

v = [1 2 3]
v = [1; 2; 3]
v = 1:0.1:2   % from 1 to 2, with stepsize of 0.1. Useful for plot axes
v = 1:6       % from 1 to 6, assumes stepsize of 1 (row vector)

C = 2*ones(2,3) % same as C = [2 2 2; 2 2 2]
w = ones(1,3)   % 1x3 vector of ones
w = zeros(1,3)
w = rand(1,3) % drawn from a uniform distribution 
w = randn(1,3)% drawn from a normal distribution (mean=0, var=1)
w = -6 + sqrt(10)*(randn(1,10000));  % (mean = -6, var = 10) - note: add the semicolon
hist(w)    % plot histogram using 10 bins (default)
hist(w,50) % plot histogram using 50 bins
% note: if hist() crashes, try "graphics_toolkit('gnu_plot')" 

I = eye(4)   % 4x4 identity matrix

% help function
help eye
help rand
help help

Control statements: for, while, if statements

v = zeros(10,1);
for i=1:10, 
    v(i) = 2^i;
end;
% Can also use "break" and "continue" inside for and while loops to control execution.

i = 1;
while i <= 5,
  v(i) = 100; 
  i = i+1;
end

i = 1;
while true, 
  v(i) = 999; 
  i = i+1;
  if i == 6,
    break;
  end;
end

if v(1)==1,
  disp('The value is one!');
elseif v(1)==2,
  disp('The value is two!');
else
  disp('The value is not one or two!');
end

Functions / Vectorization 등 참고해서 공부할 것!