Probes
About Probes
Probes () monitor the development of a scalar-valued quantity (real or complex-valued number) from a time-dependent, frequency-domain, or parametric simulation by two different results presentations: tabulated data and 1D graph plots. You can probe while solving, as a monitor and diagnostic tool, and probe after the computation is finished for results analysis. On top of this functionality, a probe variable in the model component’s namespace and with a global evaluation scope is also defined. The probe variable’s name appears in the Probe variable field. You can use this variable as any other variable in, for example, equations, boundary conditions, or a stop condition, as well as for global evaluations.
The probe variables are not just optional extra variables. They are used for the internal evaluation of probes while solving (if enabled). The probe-while-solving functionality can also update the results at steps taken by the solver, which are not necessarily stored in the solution object. This can be used, for example, to get high resolution time-dependent output from probes without storing all the fields for these times.
When evaluating probes during postprocessing, the probe variables are not used. Instead, a corresponding results functionality is used. The data used is always based on what is stored in the solution.
Accumulated probe tables accumulate probe results from an outer Parametric Sweep or from another outer sweep functionality. These tables are always filled with data from the Result functionality for probes, and not the probe variables.
Plot while solving is a technique used to briefly interrupt the simulation and launch some predefined plot commands and then continue with the simulation. Both normal plots and graphs can be plotted for probes during the simulation.
The following types of probes are available (see Table 5-19 for the icons by space dimension):
Domain probes, boundary probes, edge probes, and point probes make it possible to probe the average, minimum, maximum, or integral of a field quantity over a domain, on a boundary, along an edge (in 3D), and at points.
Domain point probes and boundary point probes provide the value of some field quantity at a point in the domain or on a boundary. Any point within the domain or on the boundary can be defined.
Use Global variable probes () for probing the value of any global variable.
The probes automatically create a Probe Table node for displaying numerical results in the Table window and an associated plot group with a Probe Table Plot node that plots the probe data as a line graph in a separate Probe Plot window. For further processing, the probes also add datasets such as Domain Point Probe datasets (), which give access to the probe data. For further control, specify the table and plot window each probe uses.
To add a Probe to any Component:
In the Definitions toolbar, select features from the Probes menu, or
Right-click the Definitions () node and choose an option from the Probes submenu.
When the simulation has finished, click the Update Results button () in the probe Settings window (or in the Definitions toolbar) to change the settings for a probe and update the results information using the last solution in the model. Then right-click the Definitions node (or the Probes node if the Definitions nodes are grouped by type) and select Update Probes.
The update of probes can also be done while solving, when tables and probe plots are updated automatically using the probe variables.
After an update, all the probes are available as Derived Values nodes under Results. These values can be modified and reevaluated in standard ways. Note, however, that if the changes you do to probes under Results are in conflict with the probe settings then those changes will be overwritten by the probes next time you update them.
The following list contains the available probe types for each space dimension.