Volumetric Analysis is likely to be more computationally expensive than 2D analysis because extending grids to three dimensions can greatly increase the number of grid points. The analysis involves two types of data:
- Satisfaction of spatial conditions that determines at any time which grid points are active and which are inactive.
- Scalar values generated at any time by spatial calculations on all active grid points.
This type of data is always computed in batch mode in the form of intervals of satisfaction so that during animation or reporting, active or inactive status of all grid points can be determined by a simple look-up inside of the previously computed intervals.
Data that consists of scalar values for all active grid points can be evaluated at any instant in time, or it can be evaluated in batch mode at some predetermined time. In batch mode, during animation or reporting, volumetric data is set by comparing the current time with the times evaluated in batch mode and using the data from the latest preceding time.
Selecting the Compute Option
Select either batch computations or parallel computations for computing volumetric analysis:
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To initiate batch computations, right-click the Volumetric object in the Object Browser and select Volumetric-->Compute.... A progress indicator that allows you to interrupt and cancel computations is displayed.
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To initiate parallel computations, right-click the Volumetric object in the Object Browser and select Volumetric-->Compute Volumetric in Parallel .
The Compute Volumetric in Parallel option is displayed on the Volumetric menu. More information on computing volumetric in parallel can be found in the STK Parallel Computing Help.
If the Automatically recompute option is selected on the Basic-->Advanced page, computations are re-initiated each time changes are made that affect grid points or spatial calculations.