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RingProfile v1

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Summary

Calculates the sum of the counts against a circular ring.

See Also

LineProfile

Properties

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	An input workspace.
OutputWorkspace	Output	MatrixWorkspace	Mandatory	An output workspace.
Centre	Input	dbl list	0,0,0	Coordinate of the centre of the ring
MinRadius	Input	number	0	Radius of the inner ring(m)
MaxRadius	Input	number	Optional	Radius of the outer ring(m)
NumBins	Input	number	100	Number of slice bins for the output
StartAngle	Input	number	0	The angle to start from.
Sense	Input	string	Anti-ClockWise	The direction of the integration around the ring. Allowed values: [‘ClockWise’, ‘Anti-ClockWise’]

Description

RingProfile sums the counts against a ring.

Below, there is an example of the execution of the RingProfile to a Workspace2D where the position of the pixels are not associated to detector positions, but it is derived from the Axes.

The image below shows a visual interpretation for the inputs of the algorithm

The algorithm goes through each pixel and find its distance from the center. If it relies inside the defined ring, it checks the angle between the pixel position and the center and uses this information to define the bin where to put the count for that pixel.

The RingProfile is also defined for Workspace2D which has the positions based on the detectors, as you can see in the picture below.

In this case, the inputs of the algorithm is like the image below

The algorithm does to each spectrum, get the associated detector from which it get the positions. From the positions it work out if it belongs or not to the ring and in which bin it must be placed. It finally accumulate all the spectrum values inside the target bin.

It is possible to setup the StartAngle from where to starting the Ring as well as the Sense, if in clockwise direction or anti-clockwise direction. But, the resulting workspace will always place the bins in a relative angle position from the start. Which means that for anti-clockwise sense, the real 3D angle is:

RealAngle = StartAngle + Angle

While for clockwise sense, the real 3D angle is:

RealAngle = StartAngle - Angle

Usage

Example - A complete Circle - no inner radius

ws = CreateSampleWorkspace("Histogram","Multiple Peaks")
wsOut = RingProfile(ws,Centre=[0,5,10],MaxRadius=5)

print("The RingProfile has been calculated with {} bins".format(wsOut.blocksize()))

Output:

The RingProfile has been calculated with 100 bins

Example - A ring

ws = CreateSampleWorkspace("Histogram","Multiple Peaks")
wsOut = RingProfile(ws,Centre=[0,5,10],MinRadius=1,MaxRadius=5,NumBins=200)

print("The RingProfile has been calculated with {} bins".format(wsOut.blocksize()))

Output:

The RingProfile has been calculated with 200 bins

Categories: AlgorithmIndex | Transforms\Grouping

Source

C++ header: RingProfile.h

C++ source: RingProfile.cpp