wrong calculation of inverse matrix

1 Ansicht (letzte 30 Tage)
bencsl
bencsl am 7 Apr. 2019
Kommentiert: Torsten am 8 Apr. 2019
i have got a matrix
a=[ 8.371925000000001 -2.352900000000000 -4.033370000000001 1.019405000000000 -0.588200000000000;
-2.352900000000000 4.876890000000000 0 -0.588200000000000 1.044959999999999;
-4.033337000000000 0 4.033337000000000 0.000000000000000 0;
-1.064795000000001 0.588200000000000 0 8.113875000000000 8.113875000000000;
0.588200000000000 -1.093040000000000 0 -2.352900000000000 -2.352900000000000]
inv(a)
which give out
0.355615858390428 0.350051331178662 0.355618767972078 0.250754989305270 0.931280985155553
0.107719602768672 0.106034051782392 0.107720484110075 -0.238400306760741 -0.801950621197803
0.355615858390428 0.350051331178662 0.603552426875364 0.250754989305270 0.931280985155553
-0.165804799871048 -0.775520233961580 -0.165806156454541 -0.962196522948301 -3.621064878674608
0.204663830554452 0.813771214895349 0.204665505075180 1.135631499365114 3.801414057331816
and the ans is wrong, did i get any thing wrong?
螢幕快照 2019-04-08 上午2.12.14.png
  4 Kommentare
David Goodmanson
David Goodmanson am 7 Apr. 2019
Hi bencsl,
for what reason are you thinking that the answer is wrong? I tried b = inv(a) and got your Matlab result. Then checking a*b vs the identity matrix,
max(max(abs(b*a-eye(5))))
ans = 3.5527e-15 % should be small
so if any inverse is incorrect, it's the one in the image.
Torsten
Torsten am 8 Apr. 2019
Maybe you have to consider more digits for the entries in matrix a to get the result in the image.

Melden Sie sich an, um zu kommentieren.

Antworten (0)

Kategorien

Mehr zu Creating and Concatenating Matrices finden Sie in Help Center und File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by