# Linear Solvers and Krylov Methods (KSP)

The `KSP` class provides an easy-to-use interface to the combination of
a Krylov subspace iterative method and a preconditioner `PC` for the solution of linear systems and some least squares problems. See
`PETSCREGRESSORLINEAR` for additional regression (least squares) solvers.


<A HREF="../../../../../src/ksp/ksp/tutorials/index.html">Examples</A><BR>


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Source files
<p><a href="gmreig.c.html">gmreig.c</a><br>
<a href="borthog2.c.html">borthog2.c</a><br>
<a href="borthog.c.html">borthog.c</a><br>
<a href="gmpre.c.html">gmpre.c</a><br>
<a href="gmres.c.html">gmres.c</a><br>
<a href="gmresimpl.h.html">gmresimpl.h</a><br>
<a href="gmres2.c.html">gmres2.c</a><br>

<p>
Directories
<p><a href="agmres/index.html">agmres</a><br>
<a href="pipefgmres/index.html">pipefgmres</a><br>
<a href="fgmres/index.html">fgmres</a><br>
<a href="lgmres/index.html">lgmres</a><br>
<a href="ftn-custom/index.html">ftn-custom</a><br>
<a href="pgmres/index.html">pgmres</a><br>
<a href="dgmres/index.html">dgmres</a><br>