STBurn -- Burn Simulation
Having read the information on the previous page, you will figure out quickly how to use it. There is balloon/tool tip help for most tunable parameters.
STBurn will do complete burn simulations as fast as it can. I really put some effort into making the algorithm fast (and it actually outperforms quite a lot the an older burn version of some other former student...). To see how fast it is, the sps= value in the right top displays the complete burn simulations per second.
The program works as follows: It repeatedly does a complete burn sim
meaning: it creates a new forest with some tree density, automatically
ignites it (as set in the Ignition box), runs the sim's time ticks
until no tree is burning any more. Now, the program knows:
the fraction of burnt trees and the duration of the fire (in time ticks).
If the statistics window has the input focus, you can switch on the
different components using the keys e,c and d as indicated at the bottom
of the window. The X-axis displays the tree density, the Y-axis is
primarily the fraction of burned trees. Each simulation is given
a blue pixel (matching tree density and burned fratction). The blue points
are averaged together for every 0.01% tree density and displayed using
the red curve. The amber vertical bars visualize the standard deviation
of the fraction of burnt trees.
It may seem unexpected that the diagram goes up in the left bottom corner but the reason is simple: It's the (auto-) ignition. If you have a tree density of, say, 0.005 and ignite 5 of the trees then this may already be 20% of all trees. The fire will not spread but as we initially set fire on 20% of the trees, the fraction will stay 20% at the end of the sim and be displayed.