Code covered by the BSD License

# Don't let that INV go past your eyes; to solve that system, FACTORIZE!

### Tim Davis (view profile)

14 May 2009 (Updated )

A simple-to-use object-oriented method for solving linear systems and least-squares problems.

### Editor's Notes:

This file was selected as MATLAB Central Pick of the Week

test_functions
```function err = test_functions
%TEST_FUNCTIONS test various functions applied to a factorize object
% on a set of matrices
%
% Example:
%   test_functions
%

% Copyright 2011-2012, Timothy A. Davis, http://www.suitesparse.com

fprintf ('\n----- Test functions:\n') ;
reset_rand ;
err = 0 ;

err = max (err, test_function ([ ])) ;
err = max (err, test_function ([ ], 'ldl', 1)) ;
err = max (err, test_function (eye (4))) ;
err = max (err, test_function (eye (4,3))) ;
err = max (err, test_function (eye (3,4))) ;

err = max (err, test_function (inf*eye (4))) ;
err = max (err, test_function (inf*eye (4,3))) ;
err = max (err, test_function (inf*eye (3,4))) ;

err = max (err, test_function (nan*eye (4))) ;
err = max (err, test_function (nan*eye (4,3))) ;
err = max (err, test_function (nan*eye (3,4))) ;

A = rand (3) ;
err = max (err, test_function (A'*A, [ ], 1)) ;
err = max (err, test_function (A, 'svd', 1)) ;
err = max (err, test_function) ;

A = rand (10) ;
A = A' + A + 20*eye(10) ;
err = max (err, test_function (A, 'svd', 1)) ;
err = max (err, test_function (A, 'chol', 1)) ;

for imaginary = 0:1
for m = 1:6
for n = 1:6
fprintf ('.') ;
A = rand (m,n) ;
if (imaginary)
A = A + 1i * rand (m,n) ;
end
err = max (err, test_function (A)) ;
A = sparse (A) ;
err = max (err, test_function (A)) ;
if (m < n)
A = A*A'  ;
else
A = A'*A  ;
end
err = max (err, test_function (A)) ;
A = full (A) ;
err = max (err, test_function (A)) ;
end
end
end

fprintf ('\ntest_functions, max error: %g\n', err) ;
```