#include "slepcrg.h" PetscErrorCode RGRingSetParameters(RG rg,PetscScalar center,PetscReal radius,PetscReal vscale,PetscReal start_ang,PetscReal end_ang,PetscReal width)Logically Collective
rg | - the region context | |
center | - center of the ellipse | |
radius | - radius of the ellipse | |
vscale | - vertical scale of the ellipse | |
start_ang | - the right-hand side angle | |
end_ang | - the left-hand side angle | |
width | - width of the ring |
-rg_ring_center | - Sets the center | |
-rg_ring_radius | - Sets the radius | |
-rg_ring_vscale | - Sets the vertical scale | |
-rg_ring_startangle | - Sets the right-hand side angle | |
-rg_ring_endangle | - Sets the left-hand side angle | |
-rg_ring_width | - Sets the width of the ring |
The start and end angles are expressed as a fraction of the circumference. The allowed range is [0..1], with 0 corresponding to 0 radians, 0.25 to pi/2 radians, and so on. It is allowed to have startangle>endangle, in which case the ring region crosses over the zero angle.
In the case of complex scalars, a complex center can be provided in the command line with [+/-][realnumber][+/-]realnumberi with no spaces, e.g. -rg_ring_center 1.0+2.0i
When PETSc is built with real scalars, the center is restricted to a real value, and the start and end angles must be such that the region is symmetric with respect to the real axis.