topic Error in documentation in Intel® oneAPI Math Kernel Library

Error in documentation

renorm2 — Wed, 03 Feb 2016 04:37:17 GMT

Here https://software.intel.com/en-us/node/520871 in packed storage description.

This k(i, j) = i - 1 + (j - 1)/2 seems to be incorrect.

pls clarify why do you think

Gennady_F_Intel — Wed, 03 Feb 2016 16:00:43 GMT

pls clarify why do you think this is wrong description

Index k doesn't cover the

renorm2 — Wed, 03 Feb 2016 16:25:00 GMT

Index k doesn't cover the entire range from 1 to n*(n + 1)/2 needed to store all elements of symmetric matrix.

Also, k is 0 when both i and j are equal to 1, while Fortran arrays are 1 based.

Hi,

Konstantin_A_Intel — Thu, 04 Feb 2016 06:39:00 GMT

Hi,

You're right, there's an error in formula. It should be i-1+j*(j-1)/2 instead. However, it is correct that k(1,1)=0 as the link you were referred to is C documentation. In C documentation, we provide indices in C array notation. If you need an index in Fortran array, your formula would be i+j*(j-1)/2

Thank you very much for finding this! We will fix it ASAP.

Best regards,

Konstantin

status - escalated. we will

Gennady_F_Intel — Thu, 04 Feb 2016 07:35:19 GMT

status - escalated. we will let you know when the fix the problem.