Module Data

*** WILL BE REWRITTEN ***

Align two datasets by shifting Y coordinate.

Works on multiple data lists at a time. Each dataset is shifted to match with the previous dataset AFTER the previous one has already been shifted.

e.g. for the third dataset y_new = zeropoint + shifts[1]*shifts[2]*y

The shifts between datasets are multiplicative, the first dataset is shifted additively by the keyword zeropoint.

At least 3 points of overlap are required!

Parameters:

• datalists (list[list[(.,.)]]) - two or more 2d lists of data giving (x,y)
• xmin (float or list) - the lower boundar(y)(ies) of the overlapping region, used for alignment. Must be 1 value for 2 datasets, n-1 values for more
• xmax (float or list) - the upper boundar(y)(ies) of the overlapping region, used for alignment. Must be 1 value for 2 datasets, n-1 values for more
• zeropoint (float) - The first dataset is shifted additively with this value

  (default: 0)

• p0 (list) - initial parameters for fitting function definition

  (default: [1,0,1.5,-2.5])

Returns: (list[list[(.,.)]], list)

The datasets are returned as given, but with shifted Y-values, and the shifts used (first value additively, rest multiplicatively)

Perform convolution on lists with a Gaussian filter.

Reduce the input grid to the target grid by integration.

Parameters:

• x_in (array) - The input x-values
• y_in (array) - The input y-values
• x_out (array) - The target x-grid
• widths (array) - The full width/half maximum spectral resolution as a function of wavelength, i.e. the fwhm of the gaussian
• factor (int) - the sigma factor for determining the window pushed through the gaussian filter. This avoids having to convolve the whole input grid, which takes a lot of time. Beyond sigma*factor the contribution of the y values is assumed to be negligible.

  (default: 5)

• oversampling (int) - oversampling factor of the target x-grid with respect to the given spectral resolution.

  (default: 1)

Returns: list

The resulting y-values

Convolves an intensity-versus-velocity profile with an instrumental Gaussian profile of width 'sigma'

by Kristof Smolders

Parameters:

• xx (array) - x values
• yy (array) - y values, if None, the y values are assumed to be included in xx, in its second dimension.

  (default: None)

• sigma (float) - width of the gaussian profile

  (default: 3)

Returns: array

The new y values after convolution

Reduce the size of a 1d-array.

Two modes are available:

• average: subsequent n=stepsize elements are averaged
• remove: keep one element every n=stepsize elements

The average mode can be used when, e.g., reading MCMax output, where the density/temperature/... grids are given for radial and angular coordinates. In case only the radial points are needed, the stepsize would then be the number of angular grid cells.

Parameters:

• arr (np.array) - The array to be reduced
• stepsize (int) - The number of subsequent elements to average/frequency of element removal.
• cutoff (float) - A cutoff value below which no reduction is done. Default if the full array is to be reduced. Only relevant for mode == 'remove'.

  (default: None)

• mode (string) - The reduction mode, either 'average' or 'remove'. If the mode is not recognized, it is assumed to be 'average'.

  (default: 'average')

Returns: np.array

The reduced array

Get the RMS of a flux array in a given wavelength range. If no wavelengths are given, the RMS of the whole array is given.

If the array used for RMS calculation is too small, None is returned.

The mean should already be subtracted!

A 1-sigma clipping of the flux array can be done by providing limits.

Parameters:

• flux (array) - The wavelength array
• limits ((float,float)) - Flux limits if flux clipping (1 sigma!) is needed before RMS calculation. None for both limits implies no clipping. None for one of the limits implies a half-open interval. (lower limit,upper limit)

  (default: (None,None))

• wave (array) - The wavelength array. If default, the RMS is calculated of the whole flux array
• wmin (float) - The minimum wavelength. If not given, the minimum wavelength is the first entry in the wave array

  (default: None)

• wmin (float) - The maximum wavelength. If not given, the maximum wavelength is the last entry in the wave array

  (default: None)

• minsize (int) - The minimum size of the selected array before proceeding with the noise calculation. 0 if no min size is needed.

  (default: 20)

• wmax (float)

Returns: float

The flux RMS between given wavelengths

Get the mean of a flux array in a given wavelength range. If no wavelengths are given, the mean of the whole array is given.

If the array used for mean calculation is too small, None is returned.

A 1-sigma clipping of the flux array can be done by providing limits.

Parameters:

• flux (array) - The wavelength array
• limits ((float,float)) - Flux limits if flux clipping (1 sigma!) is needed before Meancalculation. None for both limits implies no clipping. None for one of the limits implies a half-open interval.

  (default: (None,None))

• wave (array) - The wavelength array. If default, the Mean is calculated of the whole flux array
• wmin (float) - The minimum wavelength. If not given, the minimum wavelength is the first entry in the wave array

  (default: None)

• wmin (float) - The maximum wavelength. If not given, the maximum wavelength is the last entry in the wave array

  (default: None)

• minsize (int) - The minimum size of the selected array before proceeding with the noise calculation. 0 if no min size is needed.

  (default: 20)

• wmax (float)

Returns: float

The flux mean between given wavelengths

Get the std of a flux array in a given wavelength range. If no min/max wavelengths are given, the std of the whole array is given.

If the array used for std calculation is too small, None is returned.

A 1-sigma clipping of the flux array can be done by providing limits.

Parameters:

• flux (array) - The wavelength array
• limits ((float,float)) - Flux limits if flux clipping (1 sigma!) is needed before STD calculation. None for both limits implies no clipping. None for one of the limits implies a half-open interval.

  (default: (None,None))

• wave (array) - The wavelength array. If default, the STD is calculated of the whole flux array
• wmin (float) - The minimum wavelength. If not given, the minimum wavelength is the first entry in the wave array

  (default: None)

• wmin (float) - The maximum wavelength. If not given, the maximum wavelength is the last entry in the wave array

  (default: None)

• minsize (int) - The minimum size of the selected array before proceeding with the noise calculation. 0 if no min size is needed.

  (default: 20)

• wmax (float)

Returns: float

The flux std between given wavelengths

Select the sub array of a flux, given a wavelength range. If no range is given, return the full array.

Parameters:

• flux (array) - The wavelength array
• wave (array) - The wavelength array. If default, no wavelength selection is done.
• wmin (float) - The minimum wavelength. If not given, the minimum wavelength is the first entry in the wave array

  (default: None)

• wmin (float) - The maximum wavelength. If not given, the maximum wavelength is the last entry in the wave array

  (default: None)

• wmax (float)

Returns: array

The flux in given wavelengths

Check whether the input value is a proper array.

Parameters:

• x (anything) - The input candidate array

Returns: array

an array of the input value