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<TITLE>HPL_pdlange HPL 2.0 Library Functions September 10, 2008</TITLE>
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      ALINK = "#ffff00">
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<H1>Name</H1>
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<B>HPL_pdlange</B> Compute ||A||.
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<H1>Synopsis</H1>
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<CODE>#include "hpl.h"</CODE><BR><BR>
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<CODE>double</CODE>
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<CODE>HPL_pdlange(</CODE>
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<CODE>const HPL_T_grid *</CODE>
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<CODE>GRID</CODE>,
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<CODE>const HPL_T_NORM</CODE>
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<CODE>NORM</CODE>,
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<CODE>const int</CODE>
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<CODE>M</CODE>,
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<CODE>const int</CODE>
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<CODE>N</CODE>,
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<CODE>const int</CODE>
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<CODE>NB</CODE>,
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<CODE>const double *</CODE>
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<CODE>A</CODE>,
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<CODE>const int</CODE>
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<CODE>LDA</CODE>
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<CODE>);</CODE>
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<H1>Description</H1>
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<B>HPL_pdlange</B>
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returns  the value of the one norm,  or the infinity norm,
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or the element of largest absolute value of a distributed matrix A:
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   max(abs(A(i,j))) when NORM = HPL_NORM_A,
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   norm1(A),        when NORM = HPL_NORM_1,
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   normI(A),        when NORM = HPL_NORM_I,
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where norm1 denotes the one norm of a matrix (maximum column sum) and
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normI denotes  the infinity norm of a matrix (maximum row sum).  Note
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that max(abs(A(i,j))) is not a matrix norm.
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<H1>Arguments</H1>
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<PRE>
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GRID    (local input)                 const HPL_T_grid *
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        On entry,  GRID  points  to the data structure containing the
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        process grid information.
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</PRE>
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<PRE>
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NORM    (global input)                const HPL_T_NORM
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        On entry,  NORM  specifies  the  value to be returned by this
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        function as described above.
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</PRE>
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<PRE>
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M       (global input)                const int
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        On entry,  M  specifies  the number  of rows of the matrix A.
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        M must be at least zero.
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</PRE>
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<PRE>
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N       (global input)                const int
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        On entry,  N specifies the number of columns of the matrix A.
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        N must be at least zero.
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</PRE>
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<PRE>
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NB      (global input)                const int
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        On entry,  NB specifies the blocking factor used to partition
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        and distribute the matrix. NB must be larger than one.
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</PRE>
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<PRE>
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A       (local input)                 const double *
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        On entry,  A  points to an array of dimension  (LDA,LocQ(N)),
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        that contains the local pieces of the distributed matrix A.
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</PRE>
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<PRE>
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LDA     (local input)                 const int
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        On entry, LDA specifies the leading dimension of the array A.
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        LDA must be at least max(1,LocP(M)).
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</PRE>
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<H1>See Also</H1>
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<A HREF="HPL_pdlaprnt.html">HPL_pdlaprnt</A>,
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<A HREF="HPL_fprintf.html">HPL_fprintf</A>.
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