({{, (RefLink[RegionFunction, paclet:ref/RegionFunction])
is an option for plotting functions that specifies the region to include in the plot drawn. }})

OpenersNotesSection(Spacer1)Details

The setting (RefLink[RegionFunction, paclet:ref/RegionFunction])->r specifies that a point should be included in the region when r[args] yields (RefLink[True, paclet:ref/True]).

The arguments supplied to r are as follows:

Adaptive refinement is typically used to determine the boundaries of the region specified by (RefLink[RegionFunction, paclet:ref/RegionFunction]).

The boundary of regions defined by (RefLink[RegionFunction, paclet:ref/RegionFunction]) is drawn with a style specified by the setting for (RefLink[BoundaryStyle, paclet:ref/BoundaryStyle]).

OpenersPrimaryExamplesSection(Spacer1)Examples  (2)

OpenersExampleSection0(Spacer1)Basic Examples  (2)

Plot over an annulus region:

Plot3D[x^2-y^2,{x,-3,3},{y,-3,3},RegionFunction->Function[{x,y,z},2<x^2+y^2<9]]

ContourPlot[x^2-y^2,{x,-3,3},{y,-3,3},RegionFunction->Function[{x,y,z},2<x^2+y^2<9]]

Region cuts in the radial direction:

SphericalPlot3D[1+Sin[5θ]Sin[5ϕ]/5,{θ,0,Pi},{ϕ,0,2Pi},Mesh->None,RegionFunction->(#6>0.95&),PlotStyle->FaceForm[Orange,Yellow]]

({{DocumentationFooterIconsRelatedFunction.png, ({{See Also}, {(RefLink[PlotRange, paclet:ref/PlotRange])  ▪  (RefLink[RegionPlot, paclet:ref/RegionPlot])  ▪  (RefLink[RegionPlot3D, paclet:ref/RegionPlot3D])  ▪  (RefLink[Exclusions, paclet:ref/Exclusions])  ▪  (RefLink[BoundaryStyle, paclet:ref/BoundaryStyle])  ▪  (RefLink[Filling, paclet:ref/Filling])  ▪  (RefLink[ClippingStyle, paclet:ref/ClippingStyle])  ▪  (RefLink[ClipPlanes, paclet:ref/ClipPlanes])}})}})

({{DocumentationFooterIconsRelatedTutorial.png, ({{Tutorials}, {▪(RefLinkPlain[Equations and Inequalities over Domains, paclet:tutorial/EquationsAndInequalitiesOverDomains])}, {▪(RefLinkPlain[The Representation of Solution Sets, paclet:tutorial/TheRepresentationOfSolutionSets])}, {▪(RefLinkPlain[Inequalities, paclet:tutorial/Inequalities-ManipulatingEquationsAndInequalities])}})}})

({{DocumentationFooterIconsRelatedGuide.png, ({{Related Guides}, {▪(RefLinkPlain[Inequalities, paclet:guide/Inequalities])}, {▪(RefLinkPlain[Plotting and Image Regions, paclet:guide/PlottingAndImageRegions])}, {▪(RefLinkPlain[Graphics Coordinates, paclet:guide/GraphicsCoordinates])}, {▪(RefLinkPlain[Plotting Options, paclet:guide/PlottingOptions])}, {▪(RefLinkPlain[Graphics Options & Styling, paclet:guide/GraphicsOptionsAndStyling])}, {▪(RefLinkPlain[Vector Visualization, paclet:guide/VectorVisualization])}})}})