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<H2><A Name="MA02DD">MA02DD</A></H2>
<H3>
Pack/unpack the upper or lower triangle of a symmetric matrix
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<A HREF ="#Specification"><B>[Specification]</B></A>
<A HREF ="#Arguments"><B>[Arguments]</B></A>
<A HREF ="#Method"><B>[Method]</B></A>
<A HREF ="#References"><B>[References]</B></A>
<A HREF ="#Comments"><B>[Comments]</B></A>
<A HREF ="#Example"><B>[Example]</B></A>
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<B><FONT SIZE="+1">Purpose</FONT></B>
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To pack/unpack the upper or lower triangle of a symmetric matrix.
The packed matrix is stored column-wise in the one-dimensional
array AP.
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<A name="Specification"><B><FONT SIZE="+1">Specification</FONT></B></A>
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SUBROUTINE MA02DD( JOB, UPLO, N, A, LDA, AP )
C .. Scalar Arguments ..
CHARACTER JOB, UPLO
INTEGER LDA, N
C .. Array Arguments ..
DOUBLE PRECISION A(LDA,*), AP(*)
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<A name="Arguments"><B><FONT SIZE="+1">Arguments</FONT></B></A>
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<B>Mode Parameters</B>
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JOB CHARACTER*1
Specifies whether the matrix should be packed or unpacked,
as follows:
= 'P': The matrix should be packed;
= 'U': The matrix should be unpacked.
UPLO CHARACTER*1
Specifies the part of the matrix to be packed/unpacked,
as follows:
= 'U': Upper triangular part;
= 'L': Lower triangular part.
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<B>Input/Output Parameters</B>
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N (input) INTEGER
The order of the matrix A. N >= 0.
A (input or output) DOUBLE PRECISION array, dimension
(LDA,N)
This array is an input parameter if JOB = 'P', and an
output parameter if JOB = 'U'.
On entry, if JOB = 'P', the leading N-by-N upper
triangular part (if UPLO = 'U'), or lower triangular part
(if UPLO = 'L'), of this array must contain the
corresponding upper or lower triangle of the symmetric
matrix A, and the other strictly triangular part is not
referenced.
On exit, if JOB = 'U', the leading N-by-N upper triangular
part (if UPLO = 'U'), or lower triangular part (if
UPLO = 'L'), of this array contains the corresponding
upper or lower triangle of the symmetric matrix A; the
other strictly triangular part is not referenced.
LDA INTEGER
The leading dimension of the array A. LDA >= max(1,N).
AP (output or input) DOUBLE PRECISION array, dimension
(N*(N+1)/2)
This array is an output parameter if JOB = 'P', and an
input parameter if JOB = 'U'.
On entry, if JOB = 'U', the leading N*(N+1)/2 elements of
this array must contain the upper (if UPLO = 'U') or lower
(if UPLO = 'L') triangle of the symmetric matrix A, packed
column-wise. That is, the elements are stored in the order
11, 12, 22, ..., 1n, 2n, 3n, ..., nn, if UPLO = 'U';
11, 21, 31, ..., n1, 22, 32, ..., n2, ..., if UPLO = 'L'.
On exit, if JOB = 'P', the leading N*(N+1)/2 elements of
this array contain the upper (if UPLO = 'U') or lower
(if UPLO = 'L') triangle of the symmetric matrix A, packed
column-wise, as described above.
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<A name="Comments"><B><FONT SIZE="+1">Further Comments</FONT></B></A>
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None
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<A name="Example"><B><FONT SIZE="+1">Example</FONT></B></A>
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<B>Program Text</B>
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None
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<B>Program Data</B>
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None
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<B>Program Results</B>
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None
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