LINRMS

Purpose:

Calculates a moving RMS with zero phase shift.

Syntax:

LINRMS(series, N, rampflag)

series

-

A series or table.

N

-

An integer, the number of points to compute the RMS as the series is processed.

rampflag

-

Optional. An integer, endpoint averaging flag.

0:

down

1:

up (default)

Returns:

A series or table.

Example:

W1: 1..5

W2: linrms(w1, 3)

 

W2 contains the series:

 

{1.65, 2.369, 3.215, 3.951, 4.552}

 

The X offset of the result is 1.0.

Example:

W1: integ(gnorm(1000, 1/100))

W2: movrms(w1, 10)

W3: linrms(w1, 10);overp(abs(w1), lred);overp(w2, lgreen)

 

W1 contains 1000 samples of synthesized data.

W2 performs a 10 point standard moving average.

W3 performs a zero phase moving RMS by revering the original data, computing a 10 point moving RMS, reversing the result and computing another 10 point moving RMS.

Compared to the standard moving RMS, the peaks of the resulting smoothed series line up with the absolute value of the original data.

Remarks:

LINRMS computes a zero phase moving RMS by reversing the input series, computing an N point moving RMS, reversing the result and computing another N point moving RMS. The reversal steps help ensure that the peak locations of the original data are preserved. The data is effectively smoothed with an 2N point RMS.

See Also:

AVGFILT

LINAVG

LINEXPAVG

MOVAVG

MOVAVG2

MOVMAX

MOVMIN

MOVRMS