ELhistogram

by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - EL/Edge Lists
Introduced first in SolidGeometry 5.3, Creation date: 2023-07-17, Last change: 2025-09-15

returns a list o nodes in an edge list and how often it was used

See Also: ELgraphleafs , ELplot

Example Illustration

Syntax

[nh]=ELhistogram(EL,[])

Input Parameter

EL: Edge list

Output Parameter

[nh]: list of [nodenumber usage]

Examples


A=SGbox; ELofFL(A.FL); EL=ans, view(-30,30); ELhistogram(EL)

Copyright 2023-2025 Tim C. Lueth. All rights reserved. The code is the property of Tim C. Lueth and may not be redistributed or modified without explicit written permission. This software may be used free of charge for academic research and teaching purposes only. Commercial use, redistribution, modification, or reverse engineering is strictly prohibited. Access to source code is restricted and granted only under specific agreements. For licensing inquiries or commercial use, please contact: Tim C. Lueth

Algorithm (Workflow)

This algorithm is designed to analyze an edge list (EL) and determine the frequency of each node's occurrence within that list. The function is part of the SolidGeometry library and is used to generate a histogram of node usage.

Input Parameters

EL: The edge list, which is a list of connections between nodes.
varargin: Additional optional parameters that can be passed to the function, though not explicitly used in this code.

Output Results

nh: A list containing pairs of node numbers and their corresponding usage counts.

Algorithm Steps

Identify unique nodes in the edge list using the unique function, which returns a list of unique node identifiers.
Determine the number of unique nodes using numel, which counts the elements in the list of unique nodes.
Initialize a zero vector ht of the same size as the list of unique nodes to store the usage count for each node.
Iterate over each unique node:

For each node, count its occurrences in the edge list using find and numel, and store this count in the corresponding position in ht.

Combine the list of unique nodes and their usage counts into a single matrix nh.
If no output is requested (i.e., nargout==0), generate a plot:

Create a new figure using SGfigure.
Plot the edge list using ELplot.
Set the view angle of the plot to (-30, 30) using view.

Algorithm explaination created using ChatGPT on 2025-08-18 22:41. (Please note: No guarantee for the correctness of this explanation)

Last html export of this page out of FM database by TL: 2025-09-21