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