Single crystal tool: peakfinder

Count the number of Bragg-peaks on an image

Purpose

Bragg peaks are local maxima of the background subtracted signal. Peaks are integrated and variance propagated. The centroids are reported.

Background is calculated by an iterative sigma-clipping in the polar space. The number of iteration, the clipping value and the number of radial bins could be adjusted.

This program requires OpenCL. The device needs be properly selected.

Usage:

spasify-Bragg [-h] [-V] [-v] [–debug] [–profile] [-o OUTPUT] [–save-source] [–grid-size GRID_SIZE GRID_SIZE] [–zig-zag] [-b BEAMLINE] [-p PONI] [-m MASK] [–dummy DUMMY] [–delta-dummy DELTA_DUMMY] [–radial-range RADIAL_RANGE_MIN RADIAL_RANGE_MAX] [-P POLARIZATION] [-A] [–bins BINS] [–unit UNIT] [–cycle CYCLE] [–cutoff-clip CUTOFF_CLIP] [–error-model ERROR_MODEL] [–cutoff-pick CUTOFF_PICK] [–noise NOISE] [–patch-size PATCH_SIZE] [–connected CONNECTED] [–workgroup WORKGROUP] [–device DEVICE DEVICE] [–device-type DEVICE_TYPE] [IMAGE …]

Options:

IMAGE

File with input images. All results are concatenated into a single HDF5 file.

-h, –help

show this help message and exit

-V, –version

output version and exit

-v, –verbose

show information for each frame

–debug

show debug information

–profile

show profiling information

Main arguments:

-o OUTPUT, –output OUTPUT

Output filename

–save-source

save the path for all source files

Scan options:

–grid-size GRID_SIZE GRID_SIZE

Grid along which the data was acquired

–zig-zag

The scan was performed with a zig-zag pattern

Experimental setup options:

-b BEAMLINE, –beamline BEAMLINE

Name of the instument (for the HDF5 NXinstrument)

-p PONI, –poni PONI

geometry description file

-m MASK, –mask MASK

mask to be used for invalid pixels

–dummy DUMMY

value of dynamically masked pixels

–delta-dummy DELTA_DUMMY

precision for dummy value

–radial-range RADIAL_RANGE RADIAL_RANGE

radial range as a 2-tuple of number of pixels, by default all available range

-P POLARIZATION, –polarization POLARIZATION

Polarization factor of the incident beam [-1:1], by default disabled, 0.99 is a good guess

-A, –solidangle

Correct for solid-angle correction (important if the detector is not mounted normally to the incident beam, off by default

Sigma-clipping options:

–bins BINS

Number of radial bins to consider

–unit UNIT

radial unit to perform the calculation

–cycle CYCLE

precision for dummy value

–cutoff-clip CUTOFF_CLIP

SNR threshold for considering a pixel outlier when performing the sigma-clipping

–error-model ERROR_MODEL

Statistical model for the signal error, may be `poisson`(default) or `azimuthal` (slower) or even a simple formula like ‘5*I+8’

Peak finding options:

–cutoff-pick CUTOFF_PICK

SNR threshold for considering a pixel high when searching for peaks

–noise NOISE

Quadratically added noise to the background

–patch-size PATCH_SIZE

size of the neighborhood for integration

–connected CONNECTED

Number of high pixels in neighborhood to be considered as a peak

Opencl setup options:

–workgroup WORKGROUP

Enforce the workgroup size for OpenCL kernel. Impacts only on the execution speed, not on the result.

–device DEVICE DEVICE

definition of the platform and device identifier: 2 integers. Use `clinfo` to get a description of your system

–device-type DEVICE_TYPE

device type like `cpu` or `gpu` or `acc`. Can help to select the proper device.

Current status of the program: Production