README.html CLAWPACK  
 Source file:   README.txt
 Directory:   /home/rjl/git/rjleveque/clawpack-4.x/book/chap11/redlight
 Converted:   Tue Jul 26 2011 at 12:59:04   using clawcode2html
 This documentation file will not reflect any later changes in the source file.

$\phantom{******** If you see this on the webpage then the browser could not locate *********}$
$\phantom{******** the jsMath file load.js *********}$

$\newcommand{\vector}[1]{\left[\begin{array}{c} #1 \end{array}\right]}$ $\newenvironment{matrix}{\left[\begin{array}{cccccccccc}} {\end{array}\right]}$ $\newcommand{\A}{{\cal A}}$ $\newcommand{\W}{{\cal W}}$

CLAWPACK Sample Code

Traffic flow equations.

Riemann problem for cars stopping at a red light.

The file traffic.m gives a demo of traffic flow stopping at a red light, using a Lagrangian method (tracking cars).

Plots of results

After running this code and creating plots via "make .plots", you should be able to view the plots in _plots/_PlotIndex.html .

Fortran files

Makefile [.html]
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.

setprob.f [.html]
A routine by this name is called by the library routine clawpack/1d/lib/claw1ez.f [.html] and is generally used to set any values needed for the specific problem being solved.

rp1.f [.html]
This is the Riemann solver, which takes the $q$ values stored in the arrays ql and qr and returns the waves in the array wave and speeds in the array s that result in solving the Riemann problem at each cell interface, and the fluctuations amdq and apdq. See $CLAW/doc/rp1.html for more information about 1d Riemann solvers.

qinit.f [.html]
This subroutine sets the initial data $q(x,0)$ at time $t=0$.

Python files

setrun.py [.html]
This file contains a function that specifies what run-time parameters will be used.

setplot.py [.html]
This file contains a function that specifies what plots will be done and sets various plotting parameters.

Data files

Warning: These files are generally changed when setting up a run and the versions here may not be the ones actually used.

claw.data [.html]
This file contains a number of parameter values that are used by CLAWPACK. The values in this file are read by the library routine clawpack/1d/lib/claw1ez.f [.html]. Each line contains one or more values to be read in, followed by comments that are ignored by the Fortran code but may be used by Pythons scripts.

Some parameters that you might want to modify are described in the documentation .

setprob.data [.html]
This file contains the advection velocity $u$ and various other parameters used in setting the initial conditions. Values in this file are read in by the subroutine setprob.f95 [.html].

Library routines

In addition to the Fortran routines in this library, several library routines from $CLAW/clawpack/1d/lib are used. See the Makefile [.html] to determine which ones are used.