## Summary¶

Signal processing functions

resample(xspace, vector, xspace_new, k=1, ext='error', energy_threshold=0.005, print_conservation=True)[source]

Resample (xspace, vector) on a new space (xspace_new) of evenly distributed data and whose bounds are taken as the same as `xspace`.

Uses spline interpolation to create the intermediary points. Number of points is the same as the initial xspace, times a resolution factor. Verifies energy conservation on the intersecting range at the end.

Parameters
• xspace (array) – space on which vector was generated

• vector (array) – quantity to resample

• xspace_new (array) – space on which to resample

Other Parameters
• resfactor (array) – xspace vector to resample on

• k (int) – order of spline interpolation. 3: cubic, 1: linear. Default 1.

• ext (‘error’, ‘extrapolate’, 0, 1) – Controls the value returned for elements of xspace_new not in the interval defined by xspace. If ‘error’, raise a ValueError. If ‘extrapolate’, well, extrapolate. If ‘0’ or 0, then fill with 0. If 1, fills with 1. Default ‘error’.

• energy_threshold (float or `None`) – if energy conservation (integrals on the intersecting range) is above this threshold, raise an error. If `None`, dont check for energy conservation Default 5e-3 (0.5%)

• print_conservation (boolean) – if True, prints energy conservation

Returns

array

Return type

resampled vector on evenly spaced array. Number of element is conserved.

Notes

Note that depending upon the from_space > to_space operation, sorting may be reversed.

Examples

Resample a `Spectrum` radiance on an evenly spaced wavenumber space:

```w_nm, I_nm = s.get('radiance')
w_cm, I_cm = resample_even(nm2cm(w_nm), I_nm)
```
resample_even(xspace, vector, resfactor=2, k=1, ext='error', energy_threshold=0.001, print_conservation=True)[source]

Resample (xspace, vector) on a new space (xspace_new) of evenly distributed data and whose bounds are taken as the same as `xspace`.

Uses spline interpolation to create the intermediary points. Number of points is the same as the initial xspace, times a resolution factor. Verifies energy conservation at the end.

Parameters
• xspace (array) – space on which vector was generated

• vector (array) – quantity to resample

• resfactor (float) – increase of resolution. If 1, output vector has the same number of points as the input vector. Default 2.

• k (int) – order of spline interpolation. 3: cubic, 1: linear. Default 1.

• ext (‘error’, ‘extrapolate’, 0) – Controls the value returned for elements of xspace_new not in the interval defined by xspace. If ‘error’, raise a ValueError. If ‘extrapolate’, well, extrapolate. If ‘0’ or 0, then fill with 0. Default ‘error’.

• energy_threshold (float) – if energy conservation (integrals) is above this threshold, raise an error

• print_conservation (boolean) – if True, prints energy conservation

Returns

• xspace_new (array) – evenly spaced mapping of xspace (same min, same max)

• vector_new (array) – resampled vector on evenly spaced array. Number of element is conserved.

• Note that depending upon the from_space > to_space operation, sorting may

• be reversed.

Examples

Resample a `Spectrum` radiance on an evenly spaced wavenumber space:

```w_nm, I_nm = s.get('radiance')
w_cm, I_cm = resample_even(nm2cm(w_nm), I_nm)
```