# getBLI

Compute underlying Fourier band-limited interpolant (BLI).

## Syntax

    BLI = getBLI(func)
    BLI = getBLI(func, dx)
    BLI = getBLI(func, dx, sampling_factor)
    BLI = getBLI(func, dx, sampling_factor, plot_BLI)
    BLI = getBLI(func, [], [], plot_BLI)
    [x_fine, BLI] = getBLI(func, dx, sampling_factor, plot_BLI)
    ...

## Description

`getBLI` computes the underlying band-limited interpolant (BLI) of a discretely sampled 1D function assuming a Fourier basis. The example below shows the BLI of a discrete spatial delta function.

    delta = zeros(20, 1);
    delta(end/2) = 1;
    getBLI(delta, 0.001, 10, true);

## Inputs

`func` | 1D input function

## Optional Inputs

`dx` | spatial sampling [m] (default = 1)
`upsampling_factor` | spatial sampling used to sample the underlying BLI (default = 20)
`plot_BLI` | Boolean controlling whether the discrete input function and its BLI are displayed (default = false)

## Outputs

`BLI` | band-limited interpolant
`x_fine` | x-grid for BLI

## See Also

`spect`