InterpolateEfficiencyTable

class marxs.missions.mitsnl.catgrating.InterpolateEfficiencyTable(tab, k=1)

Bases: object

Order Selector for MARXS using a specific kind of data table.

Ralf Heilmann from the SNL typically writes simulated grating efficiencies into Excel tables. Since Excel is hard to read in Python and not very suited to version control with git, those tables are converted to csv files of a certain format. A short summary of this format is given here, to help reading the code. The table contains data in 3-dimensional (wave, n_theta, order) space, flattened into a 2d table.

• Row 1 + 2: Column labels. Not used here.

• Column A: wavelength in nm.

• Column B: blaze angle in deg.

• Rest: data

For each wavelength there are multiple blaze angles listed, so Column A contains many duplicates and looks like this: [1,1,1,1,1,1,2,2,2,2,2,2,3,3,3, …]. Column B repeats like this: [1,2,3,4,5,6,1,2,3,4,5,6,1,2,3, …].

Because the wave, theta grid is regular, this class can use the scipy.interpolate.RectBivariateSpline for interpolation in each 2-d slice (order is an integer and not interpolated).

Parameters:

tabastropy.table.Table

Table as read in. Useful to access units or other meta data.

kint

Degree of spline. See scipy.interpolate.RectBivariateSpline.

Methods Summary

__call__(energies, pol, blaze)	Call self as a function.
probabilities(energies, pol, blaze)	Obtain the probabilities for photons to go into a particular order.

Methods Documentation

__call__(energies, pol, blaze)

Call self as a function.

probabilities(energies, pol, blaze)

Obtain the probabilities for photons to go into a particular order.

This has the same parameters as the __call__ method, but it returns the raw probabilities, while __call__ will draw from these probabilities and assign an order and a total survival probability to each photon.

Parameters:

energiesnp.array

Energy for each photons

polnp.array

Polarization for each photon (not used in this class)

blazenp.array

Blaze angle for each photon

Returns:

ordersnp.array

Array of orders

interpprobsnp.array

This array contains a probability array for each photon to reach a particular order