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<div id="version" align=right><b>petsc-3.4.2 2013-07-02</b></div>
<A NAME="MatCreateSeqBAIJ"><H1>MatCreateSeqBAIJ</H1></A>
Creates a sparse matrix in block AIJ (block compressed row) format. For good matrix assembly performance the user should preallocate the matrix storage by setting the parameter nz (or the array nnz). By setting these parameters accurately, performance during matrix assembly can be increased by more than a factor of 50.
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscmat.h"
PetscErrorCode MatCreateSeqBAIJ(MPI_Comm comm,PetscInt bs,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
</PRE>
Collective on <A HREF="../Sys/MPI_Comm.html#MPI_Comm">MPI_Comm</A>
<P>
<H3><FONT COLOR="#CC3333">Input Parameters</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>comm </B></TD><TD>- MPI communicator, set to <A HREF="../Sys/PETSC_COMM_SELF.html#PETSC_COMM_SELF">PETSC_COMM_SELF</A>
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>bs </B></TD><TD>- size of block
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>m </B></TD><TD>- number of rows
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>n </B></TD><TD>- number of columns
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>nz </B></TD><TD>- number of nonzero blocks per block row (same for all rows)
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>nnz </B></TD><TD>- array containing the number of nonzero blocks in the various block rows
(possibly different for each block row) or NULL
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Output Parameter</FONT></H3>
<DT><B>A </B> -the matrix
<br>
<P>
It is recommended that one use the <A HREF="../Mat/MatCreate.html#MatCreate">MatCreate</A>(), <A HREF="../Mat/MatSetType.html#MatSetType">MatSetType</A>() and/or <A HREF="../Mat/MatSetFromOptions.html#MatSetFromOptions">MatSetFromOptions</A>(),
MatXXXXSetPreallocation() paradgm instead of this routine directly.
[MatXXXXSetPreallocation() is, for example, <A HREF="../Mat/MatSeqAIJSetPreallocation.html#MatSeqAIJSetPreallocation">MatSeqAIJSetPreallocation</A>]
<P>
<H3><FONT COLOR="#CC3333">Options Database Keys</FONT></H3>
<DT><B>-mat_no_unroll </B> -uses code that does not unroll the loops in the
block calculations (much slower)
<br>
<DT><B>-mat_block_size </B> -size of the blocks to use
<br>
<P>
<P>
<H3><FONT COLOR="#CC3333">Notes</FONT></H3>
The number of rows and columns must be divisible by blocksize.
<P>
If the nnz parameter is given then the nz parameter is ignored
<P>
A nonzero block is any block that as 1 or more nonzeros in it
<P>
The block AIJ format is fully compatible with standard Fortran 77
storage. That is, the stored row and column indices can begin at
either one (as in Fortran) or zero. See the users' manual for details.
<P>
Specify the preallocated storage with either nz or nnz (not both).
Set nz=<A HREF="../Sys/PETSC_DEFAULT.html#PETSC_DEFAULT">PETSC_DEFAULT</A> and nnz=NULL for PETSc to control dynamic memory
allocation. See the <A href="../../docs/manual.pdf#nameddest=ch_mat"><A HREF="../Mat/Mat.html#Mat">Mat</A> chapter of the users manual</A> for details.
matrices.
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../Mat/MatCreate.html#MatCreate">MatCreate</A>(), <A HREF="../Mat/MatCreateSeqAIJ.html#MatCreateSeqAIJ">MatCreateSeqAIJ</A>(), <A HREF="../Mat/MatSetValues.html#MatSetValues">MatSetValues</A>(), <A HREF="../Mat/MatCreateBAIJ.html#MatCreateBAIJ">MatCreateBAIJ</A>()
<BR><P><B><P><B><FONT COLOR="#CC3333">Level:</FONT></B>intermediate
<BR><FONT COLOR="#CC3333">Location:</FONT></B><A HREF="../../../src/mat/impls/baij/seq/baij.c.html#MatCreateSeqBAIJ">src/mat/impls/baij/seq/baij.c</A>
<BR><A HREF="./index.html">Index of all Mat routines</A>
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