yChiCoeffArr

fiducia.cspline.yChiCoeffArr(energyNorm, chLen, dToY)

This is the matrix corresponding to:

\[M_y(t) + 3 M_D(t) \chi_1^{-1} \chi_3\]

which describes the cubic spline interpolation of the x-ray spectrum.

Parameters

• energyNorm (float) – normalized photon energy

• chLen (int) – Number of DANTE channels (equal to number of spline knots).

• dToY (numpy.ndarray) – Matrix for converting from \(D_i\) to \(y_i\) values in cubic spline interpolation. See dToyArr().

Returns

yChiArr – Returns a 2D matrix for a particular value of energyNorm.

Return type

numpy.ndarray

Notes

The matrix is given by:

\[M_y(t) + 3 M_D(t) \chi_1^{-1} \chi_3\]

Examples