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Tips and tricks: Difference between revisions
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<tr><td>conjugate tranpose</td><td><code>A'</code></td><td><code>A.hermitian()</code></td></tr> | <tr><td>conjugate tranpose</td><td><code>A'</code></td><td><code>A.hermitian()</code></td></tr> | ||
</table> | </table> | ||
=General= | |||
==How to declare functions inside a test block== | |||
function experience | |||
%!test | |||
%! experience_design_mat | |||
%! experience_obs_eqs | |||
%! assert (experience_design_mat == pi); | |||
%! assert (experience_obs_eqs == exp(1)); | |||
%! | |||
%! endfunction % this is a trick. | |||
%! % now we can declare functions to be used by the test above. | |||
%! | |||
%! function a = experience_design_mat | |||
%! a = pi; | |||
%! endfunction | |||
%! | |||
%! function b = experience_obs_eqs | |||
%! b = exp(1); | |||
%! % endfunction: don't add it here. Let test() do it. | |||
==A funny formatting trick with fprintf found by chance== | |||
Imagine that you want to create a text table with fprintf with 2 columns of 15 characters width and both right justified. How to do this thing? | |||
That's easy: | |||
If the variable Text is a cell array of strings (of length <15) with two columns and a certain number of rows, simply type for the kth row of Text | |||
fprintf('%15.15s | %15.15s\n', Text{k,1}, Text{k,2}); | |||
The syntax '%<n>.<m>s' allocates '<n>' places to write chars and display the '<m>' first characters of the string to display. | |||
Example: | |||
octave:1> Text={'Hello','World'}; | |||
octave:2> fprintf('%15.15s | %15.15s\n', Text{1,1}, Text{1,2}) | |||
Hello | World | |||
==Load Comma Separated Values (*.csv) files== | |||
A=textread("file.csv", "%d", "delimiter", ","); | |||
B=textread("file.csv", "%s", "delimiter", ","); | |||
inds = isnan(A); | |||
B(!inds) = num2cell(A(!inds)) | |||
B = reshape(B, | |||
This gets you a 1 column cell array. You can reshape it to the original size by using the <code>reshape</function> | |||
The next version of octave (3.6) implements the <code>CollectOutput</code> switch as seen in example 8 here: http://www.mathworks.com/help/techdoc/ref/textscan.html | |||