hexrd.imageutil module

hexrd.imageutil.fast_snip1d(y, w=4, numiter=2)

hexrd.imageutil.find_peaks_2d(img, method, method_kwargs)

hexrd.imageutil.snip1d(y, w=4, numiter=2, threshold=None)

Return SNIP-estimated baseline-background for given spectrum y.

!!!: threshold values get marked as NaN in convolution !!!: mask in astropy’s convolve is True for masked; set to NaN

hexrd.imageutil.snip1d_quad(y, w=4, numiter=2)

Return SNIP-estimated baseline-background for given spectrum y.

Adds a quadratic kernel convolution in parallel with the linear kernel.

hexrd.imageutil.snip2d(y, w=4, numiter=2, order=1)

Return estimate of 2D-array background by “clipping” peak-like structures.

2D adaptation of the peak-clipping component of the SNIP algorithm.

Parameters

y : 2-D input array w : integer (default 4)

kernel size (maximum kernel extent actually = 2 * w * order + 1)

numiterinteger (default 2)

number of iterations

orderinteger (default 1)

maximum order of filter kernel, either 1 (linear) or 2 (quadratic)

Returns

out : 2-D array with SNIP-estimated background of y

References!!!

[1] C.G. Ryan et al, “SNIP, A statistics-sensitive background treatment

for the quantitative analysis of PIXE spectra in geoscience applications,” Nucl. Instr. and Meth. B 34, 396 (1988).

[2] M. Morhac et al., “Background elimination methods for multidimensional

coincidence gamma-ray spectra,” Nucl. Instr. and Meth. A 401, 113 (1997).