FLofELinFL

by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - FL/Facet Lists
Introduced first in SolidGeometry 4.1, Creation date: 2017-08-24, Last change: 2025-09-14

finds one ore more edges in a facets list

Description

this is a search function ismember(FL,EL)

See Also: FLunique , ELofFL , ELofFLborder

Example Illustration

Syntax

[FL,ci]=FLofELinFL(FL,EL,[])

Input Parameter

`FL`:		Facet list
`EL`:		Edge List

Output Parameter

`FL`:		Faces that contain the edges
`ci`:		selection index

Examples


A=SGbox([30,20,10]); ELinFL(A.FL,[1 2])

Copyright 2017-2025 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 function, FLofELinFL, is designed to find one or more edges within a given list of facets. It is part of the SolidGeometry library and was introduced in version 4.1. The function primarily uses the ismember function to determine the presence of edges within facets.

Input Parameters

FL: This is the facet list, which is a matrix where each row represents a facet defined by three vertices.
EL: This is the edge list, which contains the edges to be searched for within the facet list.
varargin: This is an optional parameter that allows for additional arguments, though it is not used in the current implementation.

Output Results

FL: The output facet list, which includes only those facets that contain the specified edges.
ci: The selection index, which is a logical array indicating which rows of the original facet list contain the specified edges.

Algorithm Explanation

The function operates as follows:

It checks if the first two columns of the facet list FL match any row in the edge list EL using ismember with the 'rows' option.
It performs a similar check for the second and third columns of FL against EL.
It also checks the third and first columns of FL against EL.
The logical OR operator combines these three checks to create a logical index ci that identifies which facets contain the specified edges.
The function then filters the original facet list FL using this logical index to produce the output facet list containing only the relevant facets.

This function is useful for identifying which facets in a 3D model contain specific edges, which can be important for various geometric operations and analyses.

Algorithm explaination created using ChatGPT on 2025-08-18 22:52. (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