Excluders

Excluders are used to filter points in a generator based on a pair of coordinates and some attribute of the point, for example its position or duration.

ROIExcluders

ROIExcluders filter points that fall outside of a given a region of interest.

class scanpointgenerator.ROIExcluder(rois, axes)

A class to exclude points outside of regions of interest.

Parameters:

• rois (list(ROI)) – List of regions of interest
• axes (list(str)) – Names of axes to exclude points from

create_mask(*point_arrays)

Create a boolean array specifying the points to exclude.

The resulting mask is created from the union of all ROIs.

Parameters:*point_arrays (numpy.array(float)) – Array of points for each axis Returns:Array of points to exclude Return type:np.array(int8)

to_dict()

Construct dictionary from attributes.

classmethod from_dict(d)

Create a ROIExcluder from a serialised dictionary.

Parameters:d (dict) – Dictionary of attributes Returns:New instance of ROIExcluder Return type:ROIExcluder

CircularROI Example

Here we use CircularROIs to filter the points of a snake scan

from scanpointgenerator import LineGenerator, CompoundGenerator, \
ROIExcluder, CircularROI
from scanpointgenerator.plotgenerator import plot_generator

x = LineGenerator("x", "mm", 0.0, 4.0, 5, alternate=True)
y = LineGenerator("y", "mm", 0.0, 3.0, 4)
circles = ROIExcluder([CircularROI([1.0, 2.0], 2.0),
                       CircularROI([2.0, 1.0], 2.0)], ["x", "y"])
gen = CompoundGenerator([y, x], [], [])
plot_generator(gen, circles)

(Source code, png, hires.png, pdf)

And with the excluder applied

from scanpointgenerator import LineGenerator, CompoundGenerator, \
ROIExcluder, CircularROI
from scanpointgenerator.plotgenerator import plot_generator

x = LineGenerator("x", "mm", 0.0, 4.0, 5, alternate=True)
y = LineGenerator("y", "mm", 0.0, 3.0, 4)
circles = ROIExcluder([CircularROI([1.0, 2.0], 2.0),
                       CircularROI([2.0, 1.0], 2.0)], ["x", "y"])
gen = CompoundGenerator([y, x], [circles], [])
plot_generator(gen, circles)

(Source code, png, hires.png, pdf)