What's this error mean?

[truelies]

Fatal: ERROR 344 from d_error_post. d_/lin_sol_self using Aasen's
decomposition, the tridiagonal's upper triangular factor has a
small diagonal at number 10

after use this function:

call d_lin_sol_self(rtemp1, rtemp2 , rcdeltaq2)

What's this error mean?

Thank you so much!

[TimP]

That looks like an application specific message, best answered by the package documentation. On the face of it, it appears to mean that the solver detects a near singularity in the data, within the numerical accuracy.

[Steven_L_Intel1]

I'm guessing that this is an IMSL routine, but Tim's explanation is useful.

[truelies]

Thank you Tim! There is some near singular item in the matrix, do you have some methods to solve this without the error344? Thank you so much!

[TimP]

That question goes well beyond the scope of this forum, the information you have provided, and my competence. I see that Visual Numerics even posted on this topic http://www.vni.com/books/whitepapers/Aasen.html
An incomplete list of possibilities:
1. Use double precision if required
2. Bug in your program or data input
3. Formulation inappropriate to your problem (maybe even overkill?)

Not having gone so far as to attempt teaching in this area, I won't attempt to recommend textbooks.