31 December 2009 0 Comments

Matlab Quick Reference: General

My Matlab quick reference: General notes

Mini random lottery number generator.

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k = randperm(49);
n = k(1:7)
n =
37 13 6 5 33 26 41

Difference Between && and &

&& is a short-circuit version of the & logical operator meaning when entering

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a && b

Matlab first evaluates a and if it is wrong, terminates immediately without evaluating b

Example:

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if ( (x > 0) && (1/x < 3) ) % 1/x will never be evaluated with x = 0

Single quote into a string

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string = [ 'Cindy' char(39) 's exquisite something ...']
string =
Cindy's exquisite something ...

ASCII table: http://www.neurophys.wisc.edu/www/comp/docs/ascii.html

Mean without counting zeros

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x = [ 1 2 3 0 0];
u = mean( x(x~=0) );

Remove Row or Column

To remove the Nth Row, use

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 X(N, :) = [];

To remove Mth Column, use

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 X(:, M) = [];