Difference between revisions of "Octave Basics"

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(Vectors and matrices: Overhaul.)
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=== Vectors and matrices ===
 
=== Vectors and matrices ===
  
  : | .* | ./ | .^ | ' | .' | \ | length | numel | size | zeros | ones | eye | diag | rand | det | trace | inv | lu | eig | cond | expm
+
<code>:</code> , <code>.*</code> , <code>./</code> , <code>.^</code> , <code>'</code> , <code>.'</code> , <code>\</code> , {{manual|length}} , {{manual|numel}} , {{manual|size}} , {{manual|zeros}} , {{manual|ones}} , {{manual|eye}} , {{manual|diag}} , {{manual|rand}} , {{manual|det}} , {{manual|trace}} , {{manual|inv}} , {{manual|lu}} , {{manual|eig}} , {{manual|cond}} , {{manual|expm}}
 +
 
 
   x = 1:5, x(:), x(2:4), A = [11 12; 21, 22], A(1,1:end) &crarr;
 
   x = 1:5, x(:), x(2:4), A = [11 12; 21, 22], A(1,1:end) &crarr;
  

Revision as of 10:22, 14 June 2019

For the meaning of operators, see the GNU Octave manual.

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 ↵

See also