Least squares solution of nearly square overdetermined sparse linear systems
نویسندگان
چکیده
The solution of nearly square overdetermined linear systems is studied. The sparse QR technique is compared with two sparse LU-based techniques. Numerical tests with realworld and artificial matrices indicate that the LU techniques are more accurate for incompatible right-hand sides. Also, the amount of floating point operations required by LU techniques is approximately one half smaller than QR for nearly square matrices. A new derivation is presented for a direct triangular factorization approach. Extensive numerical testing was done using MATLAB and is documented in the article.
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