For displays that support it, Filters provide a way to further refine your data.

Filtering, especially expression filtering, does increase processing overhead, and may not perform well on slower devices.

## Expression Filtering

Expression filtering sets a condition which must be met for the data to pass onto your displays control.

Expressions follow the same format as Math Parameters. see Math Parameters

If the expression evaluates to 1 (TRUE), the expression criteria will be met.

## Capture only > 50% Throttle, and Filter out the Transitions before/after

For the first part of our expression, we simply need to make sure Throttle % is > 50. Using the variable wizard, we get the following variable: [50090.156]

So, we'll start our expression off with: [50090.156] > 50.

Now, we need to filter out the transitions before this period. To do that, we can use the avg(x) function. What we want is to make sure for at least 500ms (milliseconds), our throttle has been over 50%. We can use the variable wizard again, or we can simply tag on the .avg(500) to our variable like follows: [50090.156.avg(500)] > 50

We combine it with our expression to get:

[50090.156] > 50 AND [50090.156.avg(500)] > 50

Now, we need to filter out the transitions after this period. We still use the avg(x) function, but we will supply it with a -500. This will look at the data in the future and make sure it passes our function, thus, failing before our log gets to the throttle release point. Using - amounts for avg() and slope() functions only works during playback, not during live scanning. What we end up with is: [50090.156.avg(-500)] > 50

We combine it with our expression to get:

[50090.156] > 50 AND [50090.156.avg(500)] > 50 AND [50090.156.avg(-500)] > 50

If you want, you can add ()'s to clean it up, for aesthetics:

([50090.156] > 50) AND ([50090.156.avg(500)] > 50) AND ([50090.156.avg(-500)] > 50)

That's all there is to it. In English, this says:

- if -

Throttle % > 50

- and -

Throttle % has been > 50 for 500 milliseconds

- and -

Throttle % will be > 50 for 500 milliseconds

- then -

return 1 (TRUE)