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UPDATE: 28 May 2009

Error correction in beta calculations, 28 May 2009
The code for calculating mass loss and gain did not correct for double counting when working with particles in the same compartment.  This affected calculation of beta1 and beta5 matrices in simptcalc.m.  The error has now been corrected.  The correction does not  seem to change results qualitatively but can change concentrations and fluxes by about 25%.

Slight correction, 6 April 2005

There was a slight mixup in the way that  spectra were presented by simpgraph.m.  The spectra were calculated for conserved diameter but presented as for image diameter.  The corrected version calculates and displays spectra for image- equivalent diameter. The output makes this clearer by using a subscript of i to indicated the image diameter.  An example of the output is here.



Coagulation model--- last update 20 March 2001
The following programs calculate the particle size spectrum that results from a dividing algal cell. It is written in Matlab 6. If you wish to run under Matlab 5, you will need to change the references to "quadl" to "quad8" and change the use of function handles back to strings (e.g., "ode45(@rate,x,y)" to i"ode45(rate,x,y)"). Further documentation is in pdf document

The available software modules and their functions are:
  • simple.m The master module, it calls the next three matlab scripts, simpbeta.m, simpcoag.m, and simpgraph.m. These other matlab scripts can be run on their own.

  • simpbeta.m This script calculates the betas used in the coagulation calculations. It can be run separately from the other scripts, but it requires the following functions:

    simptcalc.m (the controlling function),

    betcds.m, betcsh.m (curvilinear kernels),

    betrds.m, betrsh.m (rectilinear kernels),

    betfds.m, betfsh.m (fractal kernels), and

    setvel.m (the particle settling velocity).

  • simpcoag.m This script calculates the the evolution of the particle size spectrum via coagulation. It requires the functions setvel.m (the particle settling velocity), simpcoagr.m (the function containing the rate calculations for the ode solver), and finitial.m (the function used to initialize the particle size spectrum). It also requires that the beta coefficients have been calculated by simpbeta.m. The default file for saving the result of simpbeta is "betaf.mat", although others may be chosen.

  • simpgraph.m This script graphs the results. It requires that simpcoag have been run and It requires that simpcoag have been run and the results saved as "simpout.mat." It uses the utility stamp.m to put a time stamp in the upper right hand corner.

An example of the results can be seen in the following figures:

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Last modified: May 2009