MATLAB Function Reference |

One-dimensional interpolation using the FFT method

**Syntax**

**Description**

```
y = interpft(x,n)
```

returns the vector `y`

that contains the value of the periodic function `x`

resampled to `n`

equally spaced points.

If `length(x)`

`=`

`m`

, and `x`

has sample interval `dx`

, then the new sample interval for `y`

is `dy = dx*m/n`

. Note that `n`

cannot be smaller than `m`

.

If `X`

is a matrix, `interpft`

operates on the columns of `X`

, returning a matrix `Y`

with the same number of columns as `X`

, but with `n`

rows.

```
y = interpft(x,n,dim)
```

operates along the specified dimension.

**Algorithm**

The `interpft`

command uses the FFT method. The original vector `x`

is transformed to the Fourier domain using `fft`

and then transformed back with more points.

**See Also**

interp3 | interpn |