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<TITLE>HPL_pdlange HPL 2.0 Library Functions September 10, 2008</TITLE> |
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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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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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