<html lang="en"> <head> <title>Sparse Functions - Untitled</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Untitled"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Operators-and-Functions.html#Operators-and-Functions" title="Operators and Functions"> <link rel="next" href="Return-Types-of-Operators-and-Functions.html#Return-Types-of-Operators-and-Functions" title="Return Types of Operators and Functions"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="Sparse-Functions"></a> <p> Next: <a rel="next" accesskey="n" href="Return-Types-of-Operators-and-Functions.html#Return-Types-of-Operators-and-Functions">Return Types of Operators and Functions</a>, Up: <a rel="up" accesskey="u" href="Operators-and-Functions.html#Operators-and-Functions">Operators and Functions</a> <hr> </div> <h5 class="subsubsection">21.1.4.1 Sparse Functions</h5> <p>An important consideration in the use of the sparse functions of Octave is that many of the internal functions of Octave, such as <dfn>diag</dfn>, cannot accept sparse matrices as an input. The sparse implementation in Octave therefore uses the <dfn>dispatch</dfn> function to overload the normal Octave functions with equivalent functions that work with sparse matrices. However, at any time the sparse matrix specific version of the function can be used by explicitly calling its function name. <p>The table below lists all of the sparse functions of Octave. Note that the names of the specific sparse forms of the functions are typically the same as the general versions with a <dfn>sp</dfn> prefix. In the table below, and the rest of this article the specific sparse versions of the functions are used. <!-- Table includes in comments the missing sparse functions --> <dl> <dt>Generate sparse matrices:<dd> <dfn>spalloc</dfn>, <dfn>spdiags</dfn>, <dfn>speye</dfn>, <dfn>sprand</dfn>, <dfn>sprandn</dfn>, <dfn>sprandsym</dfn> <br><dt>Sparse matrix conversion:<dd> <dfn>full</dfn>, <dfn>sparse</dfn>, <dfn>spconvert</dfn> <br><dt>Manipulate sparse matrices<dd> <dfn>issparse</dfn>, <dfn>nnz</dfn>, <dfn>nonzeros</dfn>, <dfn>nzmax</dfn>, <dfn>spfun</dfn>, <dfn>spones</dfn>, <dfn>spy</dfn> <br><dt>Graph Theory:<dd> <dfn>etree</dfn>, <dfn>etreeplot</dfn>, <dfn>gplot</dfn>, <dfn>treeplot</dfn> <!-- @dfn{treelayout} --> <br><dt>Sparse matrix reordering:<dd> <dfn>amd</dfn>, <dfn>ccolamd</dfn>, <dfn>colamd</dfn>, <dfn>colperm</dfn>, <dfn>csymamd</dfn>, <dfn>dmperm</dfn>, <dfn>symamd</dfn>, <dfn>randperm</dfn>, <dfn>symrcm</dfn> <br><dt>Linear algebra:<dd> <dfn>condest</dfn>, <dfn>eigs</dfn>, <dfn>matrix_type</dfn>, <dfn>normest</dfn>, <dfn>sprank</dfn>, <dfn>spaugment</dfn>, <dfn>svds</dfn> <br><dt>Iterative techniques:<dd> <dfn>luinc</dfn>, <dfn>pcg</dfn>, <dfn>pcr</dfn> <!-- @dfn{bicg}, @dfn{bicgstab}, @dfn{cholinc}, @dfn{cgs}, @dfn{gmres}, --> <!-- @dfn{lsqr}, @dfn{minres}, @dfn{qmr}, @dfn{symmlq} --> <br><dt>Miscellaneous:<dd> <dfn>spparms</dfn>, <dfn>symbfact</dfn>, <dfn>spstats</dfn> </dl> <p>In addition all of the standard Octave mapper functions (i.e., basic math functions that take a single argument) such as <dfn>abs</dfn>, etc. can accept sparse matrices. The reader is referred to the documentation supplied with these functions within Octave itself for further details. </body></html>