# Questions tagged [graph-drawing]

Problems related to graph drawing such as crossing numbers, layout designs, and intersection graphs.

**4**

votes

**2**answers

240 views

### “Locally Nonplanar” graph

A 2-connected $3$-connected graph $G$ is "Almost Planar" Locally Nonplanar if it has a a $2$-connected spanning subgraph $H$ and an embedding in the plane such that $H$ is planar in this embedding and ...

**5**

votes

**0**answers

43 views

### Universal point sets for 1-plane graphs

It is a notorious open problem to find a smallest set of $N$ points that
permit any $n$-vertex planar graph to be drawn in the plane without
crossings, using only those $N$ points as vertices, and ...

**0**

votes

**0**answers

27 views

### Maximum possible crossing number of a restricted tangle family

Let $T$ be a tangle (in the sense of knot theory) on $s$ strands and no loops. In general the crossing number of $T$ is unbounded, as we can twist two strands around each other any number of times. ...

**0**

votes

**0**answers

16 views

### Finding Optimal Spheric Polyhedra with Given Convex Hull Topology

I want to draw finite planar graphs in certain canonical ways.
My idea is to use a stereographic projection of the convex hull of points placed on the unit sphere in a way, that the graph induced ...

**3**

votes

**2**answers

101 views

### Number Associated with Straight-line Drawings of Hamiltonian Graphs

Is there anything known about the maximum number of simple-polygonal Hamilton cycles that a straight-line drawing of a Hamiltonian graph can have?
Put differently, if the vertices of a Hamilton ...

**5**

votes

**2**answers

446 views

### Another graph characteristic

This question concerns a method of drawing graphs and a graph characteristic about which I want to learn more.
Consider a connected directed graph with at least one node with in-degree 0 and one node ...

**3**

votes

**1**answer

224 views

### Can all crossings in a graph be moved to one point?

Consider a graph $G$ with at least two unavoidable crossings, say, the disjoint union of two copies of $K_5$. Can such a graph always be drawn so that there is only one singular point (where all ...

**4**

votes

**0**answers

168 views

### Minimal algebraic degree of symmetric unit distance embedding of Heawood graph

I'm looking at embeddings of the Heawood graph in the plane as unit distance graph. Apparently the first such embedding was given by Gerbracht, 2009 and has algebraic (over the rationals) coordinates ...

**4**

votes

**1**answer

215 views

### Example to show pairwise crossing number is not equal to crossing number

A common point of two edges in a graph drawing that is not an incident vertex is called a crossing.
The crossing number $cr(G)$ is defined to be the minimum number of crossings in any drawing of $G$....

**9**

votes

**3**answers

1k views

### Is every graph an edge-crossing graph?

Consider a circular drawing of a simple (in particular, loopless) graph $G$ in which edges are drawn as straight lines inside the circle. The crossing graph for such a drawing is the simple graph ...

**1**

vote

**1**answer

203 views

### Counting edges in embeddable CW-complexes in R^3

Using Euler's formula ($V-E+F = 2$ where $V$, $E$ and $F$ are the number of vertices, edges and faces), we can easily count the number of edges in maximal graphs that are embeddable in plane: 3n-6. I ...

**13**

votes

**1**answer

566 views

### Drawings of complete graphs with $Z(n)$ crossings

Hill conjectured that the minimum number of crossings in a drawing of the complete graph $K_n$ in the plane is exactly
$$Z(n) = \frac{1}{4} \bigg\lfloor\frac{n}{2}\bigg\rfloor \left\lfloor\frac{n-1}{...

**6**

votes

**7**answers

1k views

### Visualizing polyhedra from their 1-skeletons

Except for a few simple cases (typically pyramids and prisms) I find it hard to visualize a polyhedron from its 1-skeleton embedded in the plane, e.g. the hexahedral graph 5, as can be seen here.
...

**2**

votes

**0**answers

221 views

### A primal-dual (double) circle packing (coin graph) question

I know that any 3-connected simple planar graph with a designated outside face (outer face) has a primal-dual (double) circle packing (Brightwell-Scheinerman Theorem).
Q1- But I am not sure whether ...

**1**

vote

**1**answer

812 views

### Graph drawing: unrooted undirected tree graphs with specified edge lengths.

Has Joseph Felsenstein's equal daylight layout been analyzed by the graph drawing community? The following description is taken from his
drawtree
documentation:
"This iteratively improves an ...

**7**

votes

**0**answers

299 views

### 3-dimensional Cayley graph

I would like to see Cayley graphs drawn in 3-dimensional Euclidean space such that the vertices are represented by points and various shadows display the actions of the generators.
For example, ...

**7**

votes

**2**answers

1k views

### Planar layouts of bipartite graphs

Instances of SAT induce a bipartite graph between clauses vertices and variable vertices, and for planar 3SAT, the resulting bipartite graph is planar.
It would be very convenient if there was a ...