Hi!!

I'm trying to use "magma_zhegvx" with a simple example, but I always get the same error, described in the documentation:

http://icl.cs.utk.edu/magma/docs/zhegvx_8cpp.html

INFO (output) INTEGER

= 0: successful exit

< 0: if INFO = -i, the i-th argument had an illegal value

> 0: ZPOTRF or ZHEEVX returned an error code:

<= N: if INFO = i, ZHEEVX failed to converge;

i eigenvectors failed to converge. Their indices

are stored in array IFAIL.

> N: if INFO = N + i, for 1 <= i <= N, then the leading

minor of order i of B is not positive definite.

The factorization of B could not be completed and

no eigenvalues or eigenvectors were computed.

I'm getting INFO = 6, and my N =3, so i = 3. I really don't understand well the meaning of this error. Specifically, the phrase: "then the leading minor of order i of B is not positive definite". Would you mind explaining me this error and what does the value i=3 mean in more detail??

I'm using the following input:

itype=1; // specifies A*x = lambda*B*x

jobz='V'; // Compute eigenvalues and eigenvectors

uplo='U'; // Upper triangle of A is stored

range='I'; // 'I': the IL-th through IU-th eigenvalues will be found.

N = 3 ; // 3x3 matrix

lda = ldb = 3;

// A

cuDoubleComplex h_A[] = {{1.0,0.0}, {2.0,0.0}, {3.0,0.0},

{3.0,0.0}, {6.0,0.0}, {8.0,0.0},

{5.0,0.0}, {9.0,0.0}, {2.0,0.0}};

// B

cuDoubleComplex h_B[] = {{3.0,0.0}, {5.0,0.0}, {7.0,0.0},

{1.0,0.0}, {7.0,0.0}, {9.0,0.0},

{4.0,0.0}, {6.0,0.0}, {2.0,0.0}};

vl = vu = 0.0;

il = 1;

iu = 1..N

// Z

cuDoubleComplex h_Z[size*size];

ldz = 3 ;

The others parameters are outputs. Have I set some input parameter wrong?

Any idea of what am I doing wrong¿?

Thank you so much in advance.