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Annotate[obj,keyvalue]

sets the annotation keyvalue for the object obj.

Annotate[{obj,itemspec},keyvalue]

sets the annotation for the items in obj specified by itemspec.

Details
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Graph & Networks  
Graph annotations  
Vertex annotations  
Edge annotations  
Regions  
BoundaryMeshRegion  
MeshRegion  
CSGRegion  
Applications  
Properties & Relations  
Possible Issues  
See Also
Related Guides
History
Cite this Page

Annotate

Annotate[obj,keyvalue]

sets the annotation keyvalue for the object obj.

Annotate[{obj,itemspec},keyvalue]

sets the annotation for the items in obj specified by itemspec.

Details

  • Typically used to store key->value pairs for an object or items in an object.
  • Annotate returns the specified object with a new or modified annotation.
  • Possible objects with items that can be annotated:
  • Audiotime points and time intervals
    BoundaryMeshRegionmesh cells
    CSGRegiongeometric regions
    Graphvertices and edges
    MeshRegionmesh cells
  • Item specification itemspec for each type of object is given in its reference page.

Examples

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Basic Examples  (3)

Specify a vertex or edge annotation:

Wolfram Language code: g = CompleteGraph[4]

To label a vertex:

Wolfram Language code: Annotate[{g, 1}, VertexLabels -> "one"]

To style an edge:

Wolfram Language code: Annotate[{g, 12}, EdgeStyle -> Red]

Highlight boundary cells in a mesh:

Wolfram Language code: Annotate[{MengerMesh[2], {1, "Boundary"}}, MeshCellStyle -> Red]

Highlight a region within CSGRegion:

Wolfram Language code: Annotate[{CSGRegion[{Ball[], Cuboid[]}], {2}}, "CSGRegionStyle" -> Red]

Scope  (17)

Graph & Networks  (11)

Graph annotations  (7)

Set annotations for vertices:

Wolfram Language code: CompleteGraph[4];
Wolfram Language code: Annotate[{[image], 1}, VertexSize -> Small]

And edges:

Wolfram Language code: Annotate[{[image], 12}, EdgeLabels -> "hello"]

Set several annotations for a vertex:

Wolfram Language code: CompleteGraph[4, VertexSize -> Medium];
Wolfram Language code: Annotate[{[image], 1}, {VertexStyle -> Magenta, VertexLabels -> "hello"}]

And for an edge:

Wolfram Language code: Annotate[{[image], 12}, {EdgeStyle -> Magenta, EdgeLabels -> "hello"}]

Annotate works with undirected graphs:

Wolfram Language code: CycleGraph[3];
Wolfram Language code: Annotate[{[image], 12}, {EdgeStyle -> Brown}]

Directed graphs:

Wolfram Language code: CycleGraph[3, DirectedEdges -> True, EdgeStyle -> Arrowheads[Small]];
Wolfram Language code: Annotate[{[image], 12}, {EdgeLabels -> "hello"}]

Multigraphs graphs:

Wolfram Language code: Graph[{1, 2, 3}, {12, 23, 23, 23, 31}];
Wolfram Language code: Annotate[{[image], 12}, {EdgeStyle -> Brown}]

Mixed graphs:

Wolfram Language code: Graph[{1, 2, 3}, {12, 23, 31}, EdgeStyle -> Arrowheads[0.08]];
Wolfram Language code: Annotate[{[image], 12}, {EdgeStyle -> Brown}]

Weighted graphs:

Wolfram Language code: With[{g = CycleGraph[3], w = 0.3Range[3], pl = {Above, Right, Right} /. {Right -> {1 / 2, {-0.4, 1 / 2}}, Above -> {1 / 2, {1 / 2, 0}}}}, Graph[VertexList[g], EdgeList[g], EdgeWeight -> w, VertexShapeFunction -> "Name", EdgeLabels -> Thread[EdgeList[g] -> MapThread[Placed, {w, pl}]], VertexCoordinates -> GraphEmbedding[g]]];
Wolfram Language code: Annotate[{[image], 12}, {EdgeStyle -> Dashed}]

Vertex annotations  (2)

Standard vertex annotations include VertexStyle:

Wolfram Language code: g = CompleteGraph[4, VertexSize -> Medium]
Wolfram Language code: Annotate[{g, 4}, VertexStyle -> Red]

VertexLabels:

Wolfram Language code: Annotate[{g, 1}, VertexLabels -> "one"]

VertexSize:

Wolfram Language code: Annotate[{g, 1}, VertexSize -> Tiny]

VertexShape:

Wolfram Language code: Annotate[{g, 1}, VertexShape -> [image]]

VertexShapeFunction:

Wolfram Language code: Annotate[{g, 2}, VertexShapeFunction -> "Square"]

Non-visual annotations include VertexWeight:

Wolfram Language code: Annotate[{g, 1}, VertexWeight -> 100]
Wolfram Language code: AnnotationValue[{%, 1}, VertexWeight]

Set a custom annotation:

Wolfram Language code: CompleteGraph[4];
Wolfram Language code: Annotate[{[image], 2}, "Material" -> "Wood"]
Wolfram Language code: AnnotationValue[{%, 2}, "Material"]

Edge annotations  (2)

Standard edge annotations include EdgeStyle:

Wolfram Language code: g = CompleteGraph[4]
Wolfram Language code: Annotate[{g, 12}, EdgeStyle -> Brown]

EdgeLabels:

Wolfram Language code: Annotate[{g, 12}, EdgeLabels -> 12]

EdgeShapeFunction:

Wolfram Language code: Annotate[{g, 34}, EdgeShapeFunction -> "HalfFilledDoubleArrow"]

Non-visual annotations include EdgeWeight:

Wolfram Language code: Annotate[{g, 12}, EdgeWeight -> 42]
Wolfram Language code: AnnotationValue[{%, 12}, EdgeWeight]

Set a custom annotation:

Wolfram Language code: CompleteGraph[4];
Wolfram Language code: Annotate[{[image], 24}, "Resistance" -> 50.]
Wolfram Language code: AnnotationValue[{%, 24}, "Resistance"]

Regions  (6)

BoundaryMeshRegion  (2)

Annotate a point:

Wolfram Language code: bmr = BoundaryMesh[Cube[]];
Wolfram Language code: Annotate[{bmr, {0, 7}}, MeshCellStyle -> {PointSize[Large], Red}]

Edge:

Wolfram Language code: Annotate[{bmr, {1, 9}}, MeshCellStyle -> {Thick, Red}]

Face:

Wolfram Language code: Annotate[{bmr, {2, 6}}, MeshCellStyle -> {Red}]

Annotate all mesh cells of specific dimension:

Wolfram Language code: bmr = BoundaryMesh[Cube[]];
Wolfram Language code: Table[Annotate[{bmr, {d}}, MeshCellStyle -> Red], {d, {0, 1, 2}}]

MeshRegion  (2)

Annotate a point:

Wolfram Language code: mr = MengerMesh[1];
Wolfram Language code: Annotate[{mr, {0, 7}}, MeshCellStyle -> {PointSize[Large], Red}]

Edge:

Wolfram Language code: Annotate[{mr, {1, 2}}, MeshCellStyle -> {Thick, Red}]

Face:

Wolfram Language code: Annotate[{mr, {2, 1}}, MeshCellStyle -> {Red}]

Annotate all mesh cells of specific dimension:

Wolfram Language code: mr = MengerMesh[2];
Wolfram Language code: Table[Annotate[{mr, {d}}, MeshCellStyle -> Red], {d, {0, 1, 2}}]

CSGRegion  (2)

Annotate a CSGRegion:

Wolfram Language code: csg = CSGRegion["Union", {Ball[], Cuboid[]}]
Wolfram Language code: Annotate[csg, "CSGRegionStyle" -> Red]

Annotate a child region within CSGRegion:

Wolfram Language code: csg = CSGRegion["Union", {Ball[], Cuboid[]}]
Wolfram Language code: Annotate[{csg, {2}}, "CSGRegionStyle" -> Red]

Applications  (3)

Use Fold to apply Annotate repeatedly:

Wolfram Language code: g = CycleGraph[8, VertexSize -> Large]
Wolfram Language code: Fold[Annotate[{#1, #2}, VertexStyle -> ColorData[45, #2]]&, g, Range[1, 5]]

See all the partial results:

Wolfram Language code: FoldList[Annotate[{#1, #2}, VertexStyle -> ColorData[45, #2]]&, g, Range[1, 6]]

Create a graph:

Wolfram Language code: g = CompleteGraph[4]

Temporarily highlight one vertex:

Wolfram Language code: Annotate[{g, 1}, VertexSize -> Medium]

Then another:

Wolfram Language code: Annotate[{g, 2}, VertexSize -> Medium]

Highlight the edges visited during a breadth-first scan:

Wolfram Language code: g = CompleteKaryTree[4, 3, DirectedEdges -> True]
Wolfram Language code: ListAnimate[Reap[BreadthFirstScan[g, {"FrontierEdge" -> (Sow[Annotate[{g, #}, EdgeStyle -> Red]]& )}]][[2, 1]], DefaultDuration -> Length[EdgeList[g]] / 2, SaveDefinitions -> True]

Properties & Relations  (6)

Use Annotation as a wrapper to specify annotations in functions such as Graph:

Wolfram Language code: Graph[{Annotation[1, {VertexSize -> Medium, VertexStyle -> Red}], 2, 3}, {12, 23, 31}]

Use AnnotationValue to extract values:

Wolfram Language code: g = CompleteGraph[4, VertexStyle -> {1 -> Red}, VertexSize -> Small]
Wolfram Language code: AnnotationValue[{g, 1}, VertexStyle]

For undefined annotations, the value $Failed is returned:

Wolfram Language code: AnnotationValue[{g, 1}, "foo"]
Wolfram Language code: MemberQ[AnnotationKeys[{g, 1}], "foo"]

Use AnnotationValue to set annotations in a graph:

Wolfram Language code: g = CompleteGraph[4]
Wolfram Language code: AnnotationValue[{g, 1}, VertexSize] = Small;

The original graph has changed:

Wolfram Language code: g

Use AnnotationValue to unset annotations in a graph:

Wolfram Language code: g = CompleteGraph[4, VertexSize -> {1 -> Small}]
Wolfram Language code: AnnotationValue[{g, 1}, VertexSize]=.;

The original graph has changed:

Wolfram Language code: g

Use AnnotationKeys to test for the presence of an annotation:

Wolfram Language code: g = CompleteGraph[4, VertexLabels -> {1 -> one, 4 -> four}]
Wolfram Language code: MemberQ[AnnotationKeys[{g, 1}], VertexLabels]

Generate a list of vertex label rules:

Wolfram Language code: Cases[VertexList[g], v_ /; MemberQ[AnnotationKeys[{g, v}], VertexLabels] :> v -> AnnotationValue[{g, v}, VertexLabels]]

Use AnnotationDelete to remove an annotation without changing the original:

Wolfram Language code: g = CompleteGraph[4, VertexStyle -> {1 -> Red}, VertexSize -> Small]
Wolfram Language code: AnnotationDelete[{g, 1}, VertexStyle]

The original graph is unchanged:

Wolfram Language code: g

Possible Issues  (1)

AnnotationValue is typically faster than Annotate:

Wolfram Language code: g = CycleGraph[1000];
Wolfram Language code: Timing@Do[AnnotationValue[{g, v}, VertexWeight] = RandomReal[], {v, VertexList[g]}]
Wolfram Language code: g = CycleGraph[1000];
Wolfram Language code: Timing@Do[g = Annotate[{g, v}, VertexWeight -> RandomReal[]], {v, VertexList[g]}]
Wolfram Research (2020), Annotate, Wolfram Language function, https://reference.wolfram.com/language/ref/Annotate.html (updated 2025).

Text

Wolfram Research (2020), Annotate, Wolfram Language function, https://reference.wolfram.com/language/ref/Annotate.html (updated 2025).

CMS

Wolfram Language. 2020. "Annotate." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2025. https://reference.wolfram.com/language/ref/Annotate.html.

APA

Wolfram Language. (2020). Annotate. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Annotate.html

BibTeX

@misc{reference.wolfram_2026_annotate, author="Wolfram Research", title="{Annotate}", year="2025", howpublished="\url{https://reference.wolfram.com/language/ref/Annotate.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_annotate, organization={Wolfram Research}, title={Annotate}, year={2025}, url={https://reference.wolfram.com/language/ref/Annotate.html}, note=[Accessed: 12-June-2026]}