The Grid unit test has implementations to test Uniform Grid and PARAMESH. The Uniform Grid version of the test has two parts; the latter portion is also tested in PARAMESH. The test initializes the grid with a sinusoid function , distributed over a number of processors. Knowing the configuration of processors, it is possible to determine the part of the sinusoid on each processor. Since guardcells are filled either from the interior points of the neighboring processor, or from boundary conditions, it is also possible to predict the values expected in guard cells on each processor. The first part of the UG unit test makes sure that the actual received values of guard cell match with the predicted ones. This process is carried out for both cell-centered and face-centered variables.
The second part of the UG test, and the only part of the PARAMESH test, exercises the get and put data functions. Since the Grid unit has direct access to all of its own data structures, it can compare the values fetched using the getData functions against the directly accessible values and report an error if they do not match. The testing of the Grid unit is not exhaustive, and given the complex nature of the unit, it is difficult to devise tests that would do so. However, the more frequently used functions are exercised in this test.
Generic Flash Docs User 2019-10-18