# Documentation

### This is machine translation

Translated by
Mouseover text to see original. Click the button below to return to the English verison of the page.

# flipedge

Reverse edge directions

## Syntax

``H = flipedge(G)``
``H = flipedge(G,s,t)``
``H = flipedge(G,idx)``

## Description

example

````H = flipedge(G)` returns a directed graph that has the same edges as `G`, but with reversed directions. `H` contains the same node and edge properties as `G`.```

example

````H = flipedge(G,s,t)` reverses a subset of edges using the node pairs `s` and `t`.```
````H = flipedge(G,idx)` reverses a subset of edges using the edge indices `idx`.```

## Examples

collapse all

Create and plot a directed graph. Then reverse the direction of all of the edges in the graph.

```G = digraph([1 1 1 1],[2 3 4 5]); plot(G)```

```H = flipedge(G); plot(H)```

Create and plot a directed graph. Specify custom xy node coordinates for the plot.

```G = digraph([1 1 2 2 3],[2 3 3 4 5]); x = [1 0 2 -1 3]; y = [1 2 2 2.5 2.5]; plot(G,'XData',x,'YData',y)```

Reverse the direction of the edges (2,4) and (3,5), and then replot the graph.

```H = flipedge(G,[2 3],[4 5]); plot(H,'XData',x,'YData',y)```

## Input Arguments

collapse all

Input graph, specified as a `digraph` object. Use `digraph` to create a directed graph object.

Example: `G = digraph([1 2],[2 3])`

Node pairs, specified as separate arguments of scalars, vectors, character vectors, or cell arrays of character vectors. Similarly located elements in `s` and `t` specify the source and target nodes for edges in the graph. Reversing the specified edges must not produce duplicate edges in the resulting graph.

Example: `H = flipedge(G,[1 4],[2 3])` reverses the direction of the edges (1,2) and (4,3).

Example: `H = flipedge(G,{'a' 'd'},{'b' 'c'})` reverses the direction of the edges (a,b) and (d,c).

Edge indices, specified as a scalar or vector of positive integers. Each edge index corresponds to a row in the `G.Edges` table of the graph `G.Edges(idx,:)`. Reversing the specified edges must not produce duplicate edges in the resulting graph.

Example: `H = flipedge(G,3)` flips the direction of edge `G.Edges(3,:)`.

## Output Arguments

collapse all

Output graph, returned as a `digraph` object. Compared to `G`, `H` has the same nodes but some or all of the edges are in reversed direction. `H` also has the same node and edge properties as `G`.