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matrix Inverse Bug?

Anonymous's picture
Forums: 

Dear Sir!

I have find matrix inverse bug?

I am angry about open cascade matrix computation.

I have tested 6*6 matrix.

The matrix is as follows.

math_Matrix jacobian(0, 5, 0, 5);

jacobian(0,0) = 1;

jacobian(0,1) = 0;

jacobian(0,2) = 0;

jacobian(0,3) = 0;

jacobian(0,4) = 0;

jacobian(0,5) = 0;

jacobian(1,0) = 0;

jacobian(1,1) = 19;

jacobian(1,2) = -6;

jacobian(1,3) = -3;

jacobian(1,4) = 0;

jacobian(1,5) = -3;

jacobian(2,0) = 0;

jacobian(2,1) = -6;

jacobian(2,2) = 14;

jacobian(2,3) = 0;

jacobian(2,4) = 3;

jacobian(2,5) = 2;

jacobian(3,0) = 0;

jacobian(3,1) = -3;

jacobian(3,2) = 0;

jacobian(3,3) = 2;

jacobian(3,4) = 0;

jacobian(3,5) = 0;

jacobian(4,0) = 0;

jacobian(4,1) = 0;

jacobian(4,2) = 3;

jacobian(4,3) = 0;

jacobian(4,4) = 2;

jacobian(4,5) = 0;

jacobian(5,0) = 0;

jacobian(5,1) = -3;

jacobian(5,2) = 2;

jacobian(5,3) = 0;

jacobian(5,4) = 0;

jacobian(5,5) = 1;

math_Matrix Inverse = jacobian.Inverse();

Open Cascade Matrix result is as follows.

right result open cascade result

(0,0) = 1;

(0,1) = 0;

(0,2) = 0;

(0,3) = 0;

(0,4) = 0;

(0,5) = 0;

(1,0) = 0;

(1,1) = 0.1818;

(1,2) = 0; 3.700074e-017

(1,3) = 0.2727;

(1,4) = 0; -7.40149e-017

(1,5) = 0.5455;

(2,0) = 0;

(2,1) = 0;

(2,2) = 0.1818;

(2,3) = 0;

(2,4) = -0.2727;

(2,5) = -0.3636;

(3,0) = 0;

(3,1) = 0.2727;

(3,2) = 0; 2.77556e-017

(3,3) = 0.9091;

(3,4) = 0; -1.11022e-016

(3,5) = 0.8182;

(4,0) = 0;

(4,1) = 0;

(4,2) = -0.2727;

(4,3) = 0;

(4,4) = 0.9091;

(4,5) = 0.5455;

(5,0) = 0;

(5,1) = 0.5455;

(5,2) = -0.3636;

(5,3) = 0.8182;

(5,4) = 0.5455;

(5,5) = 3.3636;

Open Cascade Inverse Fuction generate 4 false result value.

Is this my mismake? I think this Open cascade matrix inverse bug.

Try this..

I looking forward to your response as soon as possible.

Thanks in advanced Best Regards.

Igor Feoktistov's picture

Hi,

I don't concider this results as wrong taking in account computer precision ~ 1.e-16

Igor

Ejun Jin. Kim's picture

Thans for your response.

I am sorry ...

Because i consider precision, It is occurred. I appricate to your response.

Thans your to point accurate explanation.

Best regards.

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