Difference between revisions of "Test"
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==New features == | ==New features == | ||
| − | * | + | *The number of tree objects (i.e. number of caliper trees) in a stand has a great impact on computation times and memory usage when running large scale simulations in PlanWise (and in RegWise depending on what data is used). For example, the time to generate treatment programs for stand may vary from 1 second to 30 seconds depending on the number of sample plots and the number of caliper trees on each plot. In some situation, execution time can be too long to be acceptable, and to overcome this a tree data aggregation algorithm has been implemented. When running a simulation, this algorithm aggregates tree records stored in the database into fewer "runtime" tree objects by grouping the trees into diameter classes. The aggregation is activated under menu Settings > Performance. For each sample plot, species group, diameter class, and tree type (tree, sapling, overstorey tree, retention tree, etc.), a new "class tree" is created that substitutes the trees in the class. The largest tree for each species group and tree type defines its own class, since the largest tree is used as an explanatory variable in certain growth and yield functions. The diameter class width is 1 cm by default, and tests show that growth projections are affected only marginally by the aggregation. The diameter of the class tree is the quadratic mean diameter of the trees in the class. |