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(if not ?fboundp ('dgesv) then load("lapack"),
'done);
'done$
(float_approx_equal_tolerance : 1e-12, 'done);
'done$
block([A, b, x],
(A : matrix ([1, -2.5], [0.375, 5]),
b : matrix ([1.75], [-0.625]),
x : dgesv (A, b),
dlange (inf_norm, b - A.x)));
0.0$
block([A, b, x],
(A : matrix ([1, -0.15], [1.82, 2]),
b : matrix ([3.7, 1, 8], [-2.3, 5, -3.9]),
x : dgesv (A, b),
dlange (inf_norm, b - A . x)));
1.110223024625157E-15$
block([A, b, x],
(A : matrix ([5, -%pi], [1b0, 11/17]),
b : matrix ([%e], [sin(1)]),
x : dgesv (A, b),
dlange (inf_norm, b - A . x)));
2.220446049250313E-16$
/*
From Intel Math Kernel Library LAPACK Examples
mkl_lapack_examples/dgesv_ex.c.htm */
block([A, b],
(A: matrix(
[ 6.80, -6.05, -0.45, 8.32, -9.67],
[ -2.11, -3.30, 2.58, 2.71, -5.14],
[ 5.66, 5.36, -2.70, 4.35, -7.26],
[ 5.97, -4.44, 0.27, -7.17, 6.08],
[ 8.23, 1.08, 9.04, 2.14, -6.87]),
b: matrix(
[ 4.02, -1.56, 9.81],
[ 6.19, 4.00, -4.09],
[ -8.22, -8.67, -4.57],
[ -7.57, 1.75, -8.61],
[ -3.03, 2.86, 8.99]),
dgesv(A, b)));
matrix([-0.8007140257202475,-0.3896213930191952,0.9554649124194904],
[-0.6952433844403112,-0.554427127353211,0.2206596269817108],
[0.593914994899136,0.842227385604611,1.900636731558973],
[1.321725609087391,-0.1038018538074622,5.357661487175357],
[0.5657561965738039,0.1057109514742748,4.040602658253425])$
(reset(float_approx_equal_tolerance), 'done);
'done$
|
