Calcium Calculator

Matlab files to accompany:

"Asymptotic analysis of buffered calcium diffusion near a point source." Gregory D. Smith, Longxiang Dai, Robert M. Miura, and Arthur Sherman. 2001. SIAM J. App. Math. 61:1816-1838 Abstract (and Online Version of the Paper for SIAP subscribers)

This page contains matlab scripts that allow calculation of calcium and buffer profiles near a point source for free calcium release.

To download all the files at once in a gzipped tar file, click on: tar file (17K).

To download all the files at once in a Windows zip file, click on: zip file (23K).

To download files one at a time go to the directory.

How to use the files:

For a description of each function, run matlab, and type "help ".

Four EXAMPLE scripts are included. They have been tested with Matlab 5.2 and 5.3.

EXAMPLE_RBA, EXAMPLE_EBA, and EXAMPLE_IBA load buffer and source parameters and then plot various approximate solutions to the equations for the buffered diffusion of calcium (RBA, EBA, IBA). To run these type:

>> example_rba

etc. at the matlab prompt. First order (plotted in red) and second order (plotted in green) versions of the approximations are compared to the numerically calculated exact solution (plotted in blue) obtained using FULLEQ. EXAMPLE_EBA also calculates LIN, the linear approximation (plotted in magenta).

Parameters are purposefully chosen so that the various approximations are marginally valid, so that the improvement of the second order approximations is obvious in the graphs. To modify parameters, edit the files RBAPARAMS.M, EBAPARAMS.M, or IBAPARAMS.M. A good exercise is to try to move the points squarely into RBA, EBA, or IBA zones, where you should see both the first and second order approximations converge to the exact solutions.

Here are the output graphs using the default parameters for RBA, EBA, and IBA.
(If you are using a graphical browser clicking on these will display the graphs in gif format. However, Matlab is not needed to view them.)

EXAMPLE_DIM loads buffer and source parameters and then plots calcium and buffer profiles near a point source using RBADIM, a dimensional version of the RBA approximation. Those more comfortable with dimensional versions of these approximations can easily modify this script to present calculations using EBADIM, IBADIM, or LINDIM.

Questions and comments about the MATLAB scripts can be sent to:

Gregory D. Smith
Department of Applied Science
The College of William and Mary
McGlothlin-Street Hall, Rm 305
Williamsburg, VA 23187

Phone: (480) 727-6661
Fax: (480) 965-8119
Email: greg@as.wm.edu
URL: http://www.as.wm.edu/Faculty/Smith.html

(Note: The U. S. government is not responsible for content of any links to non-federal sites.)

General questions and comments about this page can be sent to:

asherman@nih.gov

To go back to Sherman's Home Page click here

Last Updated 1/12/02