PlotEigValRank

PlotEigValRank(Graph, NumEigenvalues, FNmPref, DescStr)

Plots the distribution of the ranks of the first NumEigenvalues eigenvalues of the undirected graph Graph. The function creates three new files: 1) eigVal.<FNmPref>.plt (the commands used to create the plot), 2) eigVal.<FNPref>.png (the plot), and 3) eigVal.<FNmPref>.tab (the plotting data).

Parameters:

• Graph: undirected graph (input)

  A Snap.py undirected graph.

• NumEigenvalues: int (input)

  The plot will contain the ranks of the first NumEigenvalues eigenvalues’. ranks

• FNmPref: string (input)

  File name preference for the plotted graph.

• DescStr: string (input)

  Description of the graph. The string should be non-empty.

Return value:

• None

The following example shows how to plot the eigenvalue rank distribution of an undirected graph of type TUNGraph:

import snap

UGraph = snap.GenRndGnm(snap.PUNGraph, 100, 2000)

# Plot the ranks of the first 10 eigenvalues
# NOTE: Random graphs are likely to thwart the calculation of eigenvalues
snap.PlotEigValRank(UGraph, 10, "example", "Random Graph Eigenvalue Rank")