# Octave Basics

## Contents

# The very basics

`+ | - | * | / | ^ | pi | i | e | inf | eps | sin | cos | tan | exp | log | log10 | abs | sqrt | sign | round | ceil | floor | fix | = | , | ; | who | clear | help | lookfor`

x = pi, y = floor (sin (x)), z = log (exp (2013)), z / inf ↵

# Vectors and matrices

`: | .* | ./ | .^ | ' | .' | \ | length | numel | size | zeros | ones | eye | diag | rand | det | trace | inv | lu | eig | cond | expm`

x = 1:5, x(:), x(2:4), A = [11 12; 21, 22], A(1,1:end) ↵

# Graphics

`plot | semilogx | semilogy | loglog | contour | quiver | surf | mesh | meshgrid | xlabel | ylabel | zlabel | title | grid | axis | hold | subplot | figure | print`

t = 0:0.01*pi:21*pi; x = sin (t).*(exp (cos (t)) - 2*cos (4*t) + sin (t/12).^5); y = cos (t).*(exp (cos (t)) - 2*cos (4*t) + sin (t/12).^5); plot(x, y) ↵

# Scripts and functions

`@ | function | return | nargin | nargout | varargin | varargout | feval | eval`

f = @(x) x.^2, f(1:10) ↵

function v = cossum (x, n) v = cumsum (repmat (cos (x), 1, n));

# Programming elements

`== | > | < | >= | <= | != | | || | | & | && | ! | if | else | elseif | for | while |end | break | continue | pause`

for i = 1:5 if (i < 3) disp (i) else disp (i^2) end end ↵