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octave:octave [2008/08/06 15:45] devaoctave:octave [2009/04/23 13:54] (current) deva
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 =====Octave syntax and library overview===== =====Octave syntax and library overview=====
 +====Installing packages====
 +Fetch the package files from [[http://octave.sourceforge.net/|octaveforge]].
 +Then create (or add to) the file ~/.octaverc the following content:
 +<code matlab>
 +addpath(genpath('~/octave'))
 +</code>
 +And run ''pkg install packagename-1.0.0.tar.gz'' or whatever the package is called from inside octave.
 +Now the package should be available.
 +
 +====plotting====
 +<code matlab>
 +h = [1,2,3,4,5];
 +plot(h);
 +xlabel("some numbers");
 +print("myfile.pdf", "-dpdf");
 +</code>
 +This code plots a a vector with a label on the x-axis, and exports it to a pdf file.
 +
 +<code matlab>
 +h=wavread('h.wav');
 +hfft=abs(fft(h));
 +semilogx(hfft(1:end/2))
 +</code>
 +This code loads an audiofile, and plots its frequency spectrum on a logartihmical scale.
  
 ====function==== ====function====
Line 7: Line 31:
 end; end;
 </code> </code>
 +
 +====strings====
 +<code matlab>
 +mystring = 'hello world'; % create string
 +sizeof(mystring) % get length of string
 +
 +mystrilyng2 = [ mystring, 'fisk']; % concatenate two strings
 +
 +</code>
 +sizeof on works in octave. in matlab the length of a string cannot be obtained!
  
 ====string array==== ====string array====
 <code matlab> <code matlab>
-myarray = { 'hello', 'world' };+myemptyarray = {}; % create empty string array. 
 + 
 +myarray = { 'hello', 'world' }; % create array with two strings. 
 +myarray(1) % prints 'hello' 
 +myarray(3) = 'blah'; %inserts another string into the array. 
 + 
 +sizeof(myarray) % get number of elements 
 +sizeof(myarray(1)) %get length of first string 
 + 
 +% Iterate strings in string array 
 +for str = myarray 
 +  disp(str) 
 +end
  
 </code> </code>
 +Note: Arrays are 1-based, not 0-based as they usually are in real programming languages.
 +Note: sizeof is an octave-only function. size can be used to get the array size in matlab.
  
 ====if then else==== ====if then else====
octave/octave.1218030312.txt.gz · Last modified: 2008/08/06 15:45 by deva