# FZINTERP

## Purpose:

Interpolates a series by a factor using FFT zero insertion.

## Syntax:

FZINTERP(series, n)

series |
- |
An input series or array. |

n |
- |
A real, the interpolation factor, **n **> 1.0**.
**Defaults to 2.0. |

## Returns:

A series or array.

## Example:

W1: gsin(64, 1/64, 3)

W2: fzinterp(W1, 4)

W1 contains 64 samples of a 3 Hz sine wave sampled at 64 Hz.

W2 produces a 253 point interpolated 3 Hz sine wave with a sample rate
of 64 * 4 = 256 Hz.

## Example:

W3: fzinterp(W1, 3.5)

produces a 221 point interpolated 3 Hz sinewave with
a sample rate of 64 * 3.5 = 224 Hz.

## Remarks:

FZINTERP is identical to ZINTERP except that
the interpolation factor (i.e. the multiple of the original sampling rate)
is specified instead of the new rate. Although the interpolation factor
N is NOT required to be an integer, for an output length L, the relation:

N = L / length(s)

must hold, so the actual interpolation factor might differ from N. See
ZINTERP for algorithm details.

## See Also:

INTERPOLATE

POLYFIT

SPLINE

ZINTERP