ALAFF Available software

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Subsection 3.4.3 Available software

The Householder QR factorization algorithms discussed in this week are implemented as part of the LAPACK library [13] and our own libflame [46] software libraries.

It is useful to compare the programming style embraced by these efforts.

LAPACK
- dgeqrt2.f - Unblocked QR factorization.
- dgeqrt.f - Blocked QR factorization via compact WY transforms.
libflame
- FLA_QR2_UT_unb_var1.c - Unblocked QR factorization. Note: this computes not just the QR factorization, but also accumulates the \(T \) matrix needed for the blocked algorithm.
- FLA_QR2_UT_blk_var1.c - Blocked QR factorization via UT transforms.