# resample

Resampling at a different frequency

## Séquence d'appel

```y = resample(x,R);
y = resample(x,R,itrp);```

## Paramètres

x:

Input signal (1d vector)

R:

Decimation (R < 1) / upsampling (R > 1) factor, e.g. ratio between the output and input sample frequency.

itrp:

Interpolator object (default is cardinal spline)

y:

Output signal, resampled at input frequency * R

## Description

Time-domain based alternative to native Scilab intdec function (which is DFT based). The advantages compared to the `intdec` function are:

• No spectral leakages effects due to different values at the beginning and end of the signal,

• Better mastering of the frequency response (aliasing rejection), contrary to DFT method.

• The possibility to choose the interpolation algorithm to use (currently supported: cardinal cubic splines, linear and lagrange).

The default implementation is based on the cardinal cubic spline interpolator.

## Exemple

 ```fs1 = 10; fs2 = 100; // Input and output sample rates t1 = (0:1/fs1:1)'; t2 = (0:1/fs2:1)'; x = t1; // Signal to interpolate // Interpolation (intdec VS resample) yi = intdec(x, fs2/fs1); yr = resample(x, fs2/fs1); // Trunk the end of interpolated signals yi = yi(1:length(t2)); yr = yr(1:length(t2)); // Plotting clf(); plot(t1,x,'sb'); plot(t2,yi,'r'); plot(t2,yr,'g'); legend(['1:n';'intdec(1:n,8)';'resample(1:n,8)']);```

Comparison between intdec (DFT based) aand resample (interpolator based)

Note the importance of the leakage effects in intdec function, due to the hypothesis of periodicity (introducing a big discontinuity between the end and the begin of the signal).