# UPSAMPLE

## Purpose:

Inserts zeros between every Nth sample for FIR upsampling.

## Syntax:

UPSAMPLE(series, n, offset)

 series - Any series, multi-series table, or expression resulting in a series or table. n - An integer factor by which to decimate the series. Inserts N-1 samples between each sample, increasing the sample rate by a factor of N. Defaults to 1, no rate change. offset - Optional. An integer, the starting offset for the insertion. Defaults to 0, start insertion after the first sample.

## Returns:

A series, the zero inserted series.

## Example:

W1: 1..5

W2: upsample(W1, 2)

W2 == {1, 0, 2, 0, 3, 0, 4, 0, 5}

rate(w1) == 1

rate(w2) == 2

Increases the sample rate of the series in W1 by a factor of 2 by inserting a zero between every point.

## Example:

W3: 1..5

W4: upsample(W3, 3)

W4 == {1, 0, 0, 2, 0, 0, 3, 0, 0, 4, 0, 0, 5}

rate(w3) == 1

rate(w4) == 3

Increases the sample rate of the series in W3 by a factor of 3 by inserting 2 zeros between every point.

## Example:

W1: 1..5

W2: upsample(W1, 2, 2)

W2 == {0, 0, 1, 0, 0, 2, 0, 0, 3, 0, 0, 4, 0, 0, 5}

rate(w1) == 1

rate(w2) == 3

Increases the sample rate of the series in W1 by a factor of 2 by inserting a zero between every point. Two zeros are prepended to the result.

## Remarks:

UPSAMPLE increases the sample RATE of the input series by a factor of N by inserting N-1 zeros between each sample. An upsampled series can be interpolated by filtering the result with a low pass filter with a cut off frequency of Fs/2 where Fs is the original sample rate.

DECILP

DECIMATE

DOWNSAMPLE

INTERPOLATE

MERGE

REMOVE

RESAMPLE

ZEROS