Operations

Corrective operations can be applied to both the simulation and test curves before the correlation is performed. When running with a Protocol option, operations, including filtering, are automatically applied according to the protocol and will not appear in the Operations table. The Operations table is available for performing additional operations, such as correcting for differences in sign or units, allowing you to fine-tune the process as needed.

Applying Operations

Operations are accessed by clicking Operations [1] in the Correlation Table Window which will expanding the window to show the operations that have been applied. This view is minimised by default to reduce the amount of space that the Correlation Table Window occupies.

Operations can be applied to both simulation [2] and reference [3] curves.

The order of application is in the order below: (i.e., from left to right)

MULY scales the Y coordinates by the value entered (default = 1, no scaling). For example, if you want to invert the sign of a curve, enter “-1”.
ADDY offsets the Y coordinates by the value entered (default = 0, no offset).
MULX scales the X coordinates by the value input (default = 1, no scaling).
ADDX offsets the X coordinates by the value input (default = 0, no offset)
FILTER applies a CFC filter: CFC1000, CFC600, CFC180, CFC60 are supported (default = Unfiltered. Note that the filter operation is in addition any filtering that may already have been applied. For example, in the image above, 11NECKLO00WSFOYB has 'B' filter class which indicates that CFC600 filtering has already been applied. No additional filter operations have been applied so they show "Unfiltered" as the default.)

When you change the value of an operation, the textbox will change to a latent colour to indicate that the operation is “pending”:

Pending operations are only executed on channels (rows) that are selected channels.

When Auto plot is active [1] and a channel is selected [2], operations are executed automatically. Note that the latent coloured textboxes change back to white to indicate that the operations have been applied and ratings will be recomputed.

Applying Multiple Operations (Auto plot off)

If you plan on applying lots of operations, turn Auto plot off and apply a batch at a time.

When multiple rows are selected, and Auto plot off, you can choose to input a value on any row and it will be propagated to all the active rows (e.g., the input “123” [1] is applied to all the active rows in the ADDY column). Pending operations are again shown as with a latent colour background. Pressing Plot [2] will execute pending operations but only for channels (rows) that are selected.

When no rows are selected all operation inputs become active, and you can input operations on a row-by-row basis, but note that pressing Plot will not result in the operations being applied, you need to select them first.

Regularisation

After applying the MULX scaling, the curve is regularised to an X axis interval of 0.0001, which corresponds to a sampling frequency of 10kHz. This is consistent with the Euro NCAP Far Side VTC requirement to sample curves are 10kHz. Note that the regularisation happens after corrective scaling of the X axis since curves are assumed to be in SI units (i.e. time in seconds) and if MULX is used to scale a curve it is assumed to be converting the time seconds.

Filtering Operations

Care must be taken when using the filtering operations as filtering a channel curve which has already been filtered will result in different curve and therefore different results compared to filtering the unfiltered channel curve. In most cases the difference is small, but if you wish to be consistent with the Euro NCAP Far Side VTC protocol then you need to make sure that you do not apply another filter to channel curves which have already been filtered (i.e. their filter class in A, B, C, D etc.).

Saving Operations

Operations are saved in the SimVT settings file and they will be restored when loading SimVT settings. This can save a lot of time if you plan on reusing the operations you have defined.

Previous | Next