Order of checks in matrix functions

[rtrangucci]

Checks in matrix functions not ordered correctly; e.g.

mdivide_left_spd.hpp:

stan::math::check_symmetric("mdivide_left_spd", "A", A);
stan::math::check_pos_definite("mdivide_left_spd", "A", A);
stan::math::check_square("mdivide_left_spd", "A", A);
stan::math::check_multiplicable("mdivide_left_spd", 
                                                   "A", A,
                                                   "b", b);

@syclik pointed out we should be checking whether the two matrices are multiplicable before we run the check_pos_definite test. Check_pos_definite also already checks symmetry internally, so no need to call it twice.

[bob-carpenter]

The positive definiteness check should also check that the matrix is square.

• Bob

On Mar 31, 2015, at 10:33 PM, Rob Trangucci notifications@github.com wrote:

Checks in matrix functions not ordered correctly; e.g.

mdivide_left_spd.hpp:

stan::math::check_symmetric("mdivide_left_spd", "A", A); stan::math::check_pos_definite("mdivide_left_spd", "A", A); stan::math::check_square("mdivide_left_spd", "A", A); stan::math::check_multiplicable("mdivide_left_spd", "A", A, "b", b);

@syclik pointed out we should be checking whether the two matrices are multiplicable before we run the check_pos_definite test. Check_pos_definite also already checks symmetry internally, so no need to call it twice.

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[rtrangucci]

@bob-carpenter I should have added that check_pos_definite calls check_symmetric which subsequently calls check_square, so there only need to be two checks in mdivide_left_spd(A,b):

check_multiplicable(A,b)
check_pos_defininte(A)

[syclik]

This issue was moved to stan-dev/math#88