`nwpath`

Paths between nodes

Syntax

nwpath 
[netname],
[ego(nodename)
alter(nodename) | 
egoid(nodeid)
alterid(nodeid)]
generate(newnetnamestub)
sym
nwreplace
nopaths
binary
alpha(real)]

Main


`ego(nodename)`	Name of start node
`alter(nodename)`	Name of destination node
`egoid(nodeid)`	Nodeid of start node
`alterid(nodeid)`	Nodeid of destination node
`generate(newnetnamestub)`	Save paths as networks beginning with newnetnamestub
`sym`	Symmetrize network for calculation
`nwreplace`	Overwrite networks with newnetnamestub
`nopaths`	Do not print the list of paths; the results in `r()` are still returned
`binary`	Ignore the tie values of a valued network (by default they are used)
`alpha(real)`	Cost of a step along a tie of value w: 1/w^alpha (default 1 on a valued network; accepted on any network)

Description

` nwpath` calculates the shortest paths between node ego and node alter, i.e. ways how the nodes are connected with each other.

With option generate(newnetname) the command produces one new network for each valid path that is found. For example, if three paths are found between nodes ego and alter, the networks newnetnamestub_1, newnetnamestub_2, newnetnamestub_3 are produced.

Options

ego(nodename) — Must be specified and indicates the startpoint of a path.
alter(nodename) — Must be specified and indicates the endpoint of a path.
sym — Calculates everything on the symmetrized network.
generate(newnetnamestub) — Save the paths as networks. This can be used to display paths using nwplot, see example.

Remarks

It can be a good idea to save the paths between two nodes by specifying generate(newnetname) for plotting. For example,

. nwwebuse florentine, nwclear
. nwpath flobusiness, ego(medici) alter(peruzzi) generate(medici_peruzzi)

There is exactly one shortest path between medici and peruzzi, so a single network, medici_peruzzi_1, is generated (generate() is a stub - one network per shortest path found, numbered _1, _2, … - so a pair of nodes with multiple shortest paths would instead produce medici_peruzzi_1, medici_peruzzi_2, and so on). One can now use this new network to represent the edgecolor when plotting the original network.

. nwplot flobusiness, edgecolor(medici_peruzzi_1) scheme(s2network)

Examples

. nwwebuse florentine
. nwpath flobusiness, ego(medici) alter(peruzzi)

----------------------------------------
  Network: flobusiness
----------------------------------------
    Ego                  : medici
    Alter                : peruzzi
    Shortest path length : 3
----------------------------------------

  Path 1:  medici => barbadori => castellani => peruzzi
  Path 2:  medici => ridolfi => strozzi => peruzzi

Supported network types

Binary: yes. Directed: yes (sym to symmetrize first). Weighted: not applicable - any nonzero tie is treated as traversable regardless of its value; there is currently no shortest-weighted -path variant (see nwgeodesic for weighted distances). Signed: not checked. Two-mode: same as for the bipartite graph read as a one-mode network (valid; no mode-specific normalisation).

nwcommands version 3.17.6, 9 November 2026 (check your installed version)