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NAG[f01qcc] NAG[nag_real_qr] - factorization of real by matrix
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Calling Sequence
f01qcc(a, zeta, 'm'=m, 'n'=n, 'tda'=tda, 'fail'=fail)
nag_real_qr(. . .)
Parameters
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a - Matrix(1..m, 1..tda, datatype=float[8], order=C_order);
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On entry: the leading by part of the array a must contain the matrix to be factorized.
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zeta - Vector(1..n, datatype=float[8]);
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'm'=m - integer; (optional)
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Default value: the first dimension of the array a.
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On entry: , the number of rows of .
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Constraint: . .
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'n'=n - integer; (optional)
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Default value: the first dimension of the array zeta and the second dimension of the array zetathe array a.
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On entry: , the number of columns of .
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When then an immediate return is effected.
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Constraint: . .
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'tda'=tda - integer; (optional)
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On entry: the second dimension of the array a as declared in the function from which nag_real_qr (f01qcc) is called.
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Constraint: . .
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'fail'=fail - table; (optional)
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The NAG error argument, see the documentation for NagError.
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Description
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Error Indicators and Warnings
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"NE_2_INT_ARG_LT"
On entry, while . These arguments must satisfy .
"NE_INT_ARG_LT"
On entry, n must not be less than 0: .
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Further Comments
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The approximate number of floating-point operations is given by .
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Examples
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>
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m := 5:
n := 3:
tda := 3:
a := Matrix([[2, 2.5, 2.5], [2, 2.5, 2.5], [1.6, -0.4, 2.8], [2, -0.5, 0.5], [1.2, -0.3, -2.9]], datatype=float[8], order='C_order'):
zeta := Vector(3, datatype=float[8]):
NAG:-f01qcc(a, zeta, 'm' = m, 'n' = n, 'tda' = tda):
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See Also
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Dongarra J J, Moler C B, Bunch J R and Stewart G W (1979) LINPACK Users' Guide SIAM, Philadelphia
Golub G H and Van Loan C F (1996) Matrix Computations (3rd Edition) Johns Hopkins University Press, Baltimore
Wilkinson J H (1965) The Algebraic Eigenvalue Problem Oxford University Press, Oxford
f01 Chapter Introduction.
NAG Toolbox Overview.
NAG Web Site.
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