Note: Do not save the schematics after usage because they may be used in later examples.
Note: Opening the schematics from the links is best done with a Click+Drag over an existing opened instance of LTspice.
  1. With MAFv

  2. Example

    There are small errors that tend to get larger if a timestep is imposed: that's because of the behavioural source using LTspice's own delay(). Frequency analysis is possible but it will only be more accurate for f0>0; else, the value of pin 0.4 at time=0 will be used.

  3. With RRS

  4. Example

    For this schematic, if run as it is, the output wll not give the correct result. This happens when the input, at time=0, is not zero. For example, adding a -90o phase to the input will correct the response. If the input must not be altered then the only solutions are to either add the uic flag to the .TRAN card or, if it is allowed this much, to force an initial step in the beginning without affecting the rest of the waveform (.startup will not work here).
    .AC is more accurate than MAFv's and will show the same response as the FIR's moving average.

©Vlad, 2008 - 2015