gen_circle_sectorgen_circle_sectorGenCircleSectorGenCircleSectorgen_circle_sector (Operator)

Name

gen_circle_sectorgen_circle_sectorGenCircleSectorGenCircleSectorgen_circle_sector — Create a circle sector.

Signature

gen_circle_sector( : CircleSector : Row, Column, Radius, StartAngle, EndAngle : )

Description

The operator gen_circle_sectorgen_circle_sectorGenCircleSectorGenCircleSectorGenCircleSectorgen_circle_sector generates one or more circles sectors described by the center, RadiusRadiusRadiusRadiusradiusradius, StartAngleStartAngleStartAngleStartAnglestartAnglestart_angle and EndAngleEndAngleEndAngleEndAngleendAngleend_angle. If several circle sectors shall be generated the coordinates must be passed in the form of tuples.

gen_circle_sectorgen_circle_sectorGenCircleSectorGenCircleSectorGenCircleSectorgen_circle_sector only creates symmetric circle sectors with respect to the center of coordinates. To achieve this, the radius is internally rounded down to a multiple of 0.5. If an integer number is specified for the radius (i.e., 1, 2, 3, ...) an even diameter is obtained, and hence the circle can only be symmetric with respect to a center with coordinates that have a fractional part of 0.5. Consequently, internally the coordinates of the center are adapted to the closest coordinates that have a fractional part of 0.5. Here, integer coordinates are rounded down to the next smaller values with a fractional part of 0.5. For odd diameters (i.e., radius = 1.5, 2.5, 3.5, ...), the circle can only be symmetric with respect to a center with integer coordinates. Hence, internally the coordinates of the center are rounded to the nearest integer coordinates. It should be noted that the above algorithm may lead to the fact that circles with an even diameter are not contained in circles with the next larger odd diameter, even if the coordinates specified in RowRowRowRowrowrow and ColumnColumnColumnColumncolumncolumn are identical. The angles are given in radians in mathematically positive direction. See the examples illustrated in the figure below. Note, 'rad(360)'"rad(360)""rad(360)""rad(360)""rad(360)""rad(360)" is equivalent to 0. As a consequence a sector with StartAngleStartAngleStartAngleStartAnglestartAnglestart_angle = 0 and EndAngleEndAngleEndAngleEndAngleendAngleend_angle = 'rad(360)'"rad(360)""rad(360)""rad(360)""rad(360)""rad(360)" results in an empty region.

Illustration of different possible angle combinations.

If the circle extends beyond the image edge it is clipped to the current image format if the value of the system flag 'clip_region'"clip_region""clip_region""clip_region""clip_region""clip_region" is set to 'true'"true""true""true""true""true" (set_systemset_systemSetSystemSetSystemSetSystemset_system).

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

Parameters

CircleSectorCircleSectorCircleSectorCircleSectorcircleSectorcircle_sector (output_object) region(-array) → object

Generated circle sector.

RowRowRowRowrowrow (input_control) coordinates.y(-array) → (real / integer)

Line index of center.

Default value: 200.0

Suggested values: 0.0, 10.0, 50.0, 100.0, 200.0, 300.0

Typical range of values: 1.0 ≤ Row Row Row Row row row ≤ 1024.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

ColumnColumnColumnColumncolumncolumn (input_control) coordinates.x(-array) → (real / integer)

Column index of center.

Default value: 200.0

Suggested values: 0.0, 10.0, 50.0, 100.0, 200.0, 300.0

Typical range of values: 1.0 ≤ Column Column Column Column column column ≤ 1024.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

RadiusRadiusRadiusRadiusradiusradius (input_control) number(-array) → (real / integer)

Radius of circle.

Default value: 100.5

Suggested values: 1.0, 1.5, 2.0, 2.5, 3, 3.5, 4, 4.5, 5.5, 6.5, 7.5, 9.5, 11.5, 15.5, 20.5, 25.5, 31.5, 50.5

Typical range of values: 1.0 ≤ Radius Radius Radius Radius radius radius ≤ 1024.0 (lin)

Minimum increment: 1.0

Recommended increment: 10.0

Restriction: Radius > 0.0

StartAngleStartAngleStartAngleStartAnglestartAnglestart_angle (input_control) angle.rad(-array) → (real / integer)

Start angle of the circle sector.

Default value: 0.0

Suggested values: 0.0, 0.785398, 1.5708, 2.35619, 3.14159, 3.92699, 4.71239, 5.49779, 6.28318

Typical range of values: 0 ≤ StartAngle StartAngle StartAngle StartAngle startAngle start_angle ≤ 6.28318 (lin)

Restriction: 0 <= StartAngle && StartAngle <= 2 * pi

EndAngleEndAngleEndAngleEndAngleendAngleend_angle (input_control) angle.rad(-array) → (real / integer)

End angle of the circle sector.

Default value: 3.14159

Suggested values: 0.0, 0.785398, 1.5708, 2.35619, 3.14159, 3.92699, 4.71239, 5.49779, 6.28318

Typical range of values: 0 ≤ EndAngle EndAngle EndAngle EndAngle endAngle end_angle ≤ 6.28318 (lin)

Restriction: 0 <= EndAngle && EndAngle <= 2 * pi

Example (HDevelop)

read_image(Image,'fabrik')
gen_circle_sector(CircleSector,300.0,200.0,150.5,0,rad(120))
reduce_domain(Image,CircleSector,Mask)
dev_clear_window ()
dev_display (Mask)