File Exchange

## myfrenet

version 1.0 (1.97 KB) by

Construct tangent, normal and binormal vectors of a curve

Updated

Calculation of Tangent (T), Normal (N) and Binormal (B) of a continuous curve at every points of the curve.

function [T N B]=myfrenet(x,y,z,init)
% "x","y",and "z" is the coordinates of the curve. The curve also can be 2d.
% "init" is initial normal vector that user can be specified. With this input, you can freely initialize your vectors.

Although the name of the function is "myfrenet", the vectors are calculated in a different way from "frenet" equations because of some discontinuities of "frenet".

Derrivatives of the curve are calculated with spline fitting, therefore spline toolbox are required. If the toolbox are not available, users can change the derrivative calculation method such as by using "diff" or "gradient" command.

% Example
clear,clc
t=2*pi*linspace(-1/2,1/2,100).';
x=cos(t); y=sin(t); z=t;
myfrenet(x,y,z)

Mehmet OZTURK

### Mehmet OZTURK (view profile)

This code is originally based on the paper:
"Calculation of Reference Frames along a Space Curve"- Jules Bloomenthal (published in Graphics Gems, vol. 1)

So, you can cite this paper insted.

Walter

### Walter (view profile)

I will run it once and then take the mean of the Tangent vectors to use as the initial Norm vector for the second pass through.
This ensures that the orientation of the normals is typically coplanar for a more-or-less 2D curve in 3D space.
How do I cite this code/method for research purposes?

Walter

svetlana

### svetlana (view profile)

##### MATLAB Release
MATLAB 7.6 (R2008a)