Calculating a function of a matrix with a real spectrum
Let T be a square matrix with a real spectrum, and let f be an analytic function. The problem of the approximate calculation of f ( T ) is discussed. Applying the Schur triangular decomposition and the reordering, one can assume that T is triangular and its diagonal entries t i i are arranged in inc...
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| Published in: | Numerical algorithms Vol. 90; no. 3; pp. 905 - 930 |
|---|---|
| Main Authors: | , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
New York
Springer US
01.07.2022
Springer Nature B.V |
| Subjects: | |
| ISSN: | 1017-1398, 1572-9265 |
| Online Access: | Get full text |
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| Summary: | Let
T
be a square matrix with a real spectrum, and let
f
be an analytic function. The problem of the approximate calculation of
f
(
T
) is discussed. Applying the Schur triangular decomposition and the reordering, one can assume that
T
is triangular and its diagonal entries
t
i
i
are arranged in increasing order. To avoid calculations using the differences
t
i
i
−
t
j
j
with close (including equal)
t
i
i
and
t
j
j
, it is proposed to represent
T
in a block form and calculate the two main block diagonals using interpolating polynomials. The rest of the
f
(
T
) entries can be calculated using the Parlett recurrence algorithm. It is also proposed to perform some scalar operations (such as the building of interpolating polynomials) with an enlarged number of significant decimal digits. |
|---|---|
| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 |
| ISSN: | 1017-1398 1572-9265 |
| DOI: | 10.1007/s11075-021-01214-6 |