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<h2>
CLAWPACK Sample Code
</h2>

2d acoustics with a radially-symmetric solution.

Solved on a quadrilateral grid using the mapping specified in 
mapc2p.f.  This is currently set to cover a chevron-shaped region with a
grid that is not orthogonal and not smooth along one line.

See setaux.f for a description of how grid information is stored
in the aux array.   Variable coefficients for the acoustics equation are
also allowed, though in this example the they are constant and set in
setprob.f.

The data is a smooth radial hump specified in qinit.f
The 1d equation with source term is solved in subdirectory 1drad
to create an accurate reference solution.
    
Example [book/chap23/acoustics]
to accompany the book <br> &nbsp;&nbsp;
  [www.clawpack.org/book.html Finite Volume Methods for Hyperbolic Problems]
  by R. J. LeVeque.

Converted to [www.clawpack.org Clawpack 4.4] form in 2009.
        
<h4>
Plots of results
</h4>
After running this code and creating plots via "make .plots", you should be
able to view the plots in [link: _plots/_PlotIndex.html].


<h4>
Fortran files
</h4>

<dl>
<dt>[code: Makefile]
<dd> Determines which version of fortran files
are used when compiling the code with make and specifies where output and
plots should be directed.  Type "make .help" at the Unix prompt for options.

<dt>[code: driver.f]
<dd>
The driver routine allocates storage and then calls the main Clawpack
routine.

<dt>[code: setprob.f]
<dd>
A routine by this name is called by the library routine
[clawcode: clawpack/2d/lib/claw2ez.f]
and is generally used to set any values needed for the specific problem
being solved.
    
    
<dt>[code: rpn2acvq.f]
<dd> Normal Riemann solver (normal to cell interface).

<dt>[code: rpt2acvq.f]
<dd> Transverse Riemann solver.

         
<dt>[code: qinit.f]
<dd>
This subroutine sets the initial data at time $t=0$.

</dl>

<h4>
Python files
</h4>
<dl>

<dt>[code: setrun.py]
<dd> This file contains a function that
specifies what run-time parameters will be used.

Some parameters that you might want to modify are described in the
[www.clawpack.org/doc.html documentation].

<dt>[code: setplot.py]
<dd> This file contains a function that
specifies what plots will be done and
sets various plotting parameters.

</dl>


<h4>
Data files
</h4>
<font color='red'>Warning:</font> These files are generally changed
when setting up a run, usually in [code: setrun.py].

<dl>
<dt>[code: claw.data]
<dd> This file contains a number of
parameter values that are used by CLAWPACK.
The values in this file are read by the library routine
[clawcode: clawpack/2d/lib/claw2ez.f].


<dt> [code: setprob.data]
<dd> This file may contain various
parameters used in setting the initial conditions or otherwise setting up
the problem.


</dl>

<h4>Library routines</h3>

In addition to the Fortran routines in this library, several library
routines from [claw:clawpack/2d/lib] are used.  See the [code: Makefile]
to determine which ones are used.

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