# rand_angle

Below is a demonstration of the features of the `rand_angle` function

## Contents

```
clear; close all; clc;
```

## Syntax

`a=rand_angle(siz);`

## Description

This function generates a matrix or array of uniformly distributed random angles (of the size siz) in the range [0 2*pi]. The function operates by first creating angles in the range 0-pi/2. The angles are next converted to unit vectors in the unit circle. The X and Y components of these vectors are next independantly and randomly negated. This negating or flipping operation causes the vectors to uniformly but randomly span the entire cirle. Nexts the vectors are converted to an angle in the range [0 2*pi].

Plot settings for examples

markerSize=25; lineWidth=3; fontSize=35;

## Examples

siz=[500,1]; %Size of desired output a=rand_angle(siz); % The random angles

cFigure; hold on; xlabel('Angles'); ylabel('Count'); histogram(a,linspace(0,2*pi,6)); set(gca,'FontSize',fontSize); drawnow;

Visualization

%Create circle coordinates to visualize circle curve t=linspace(0,2*pi,100)'; vc=[cos(t) sin(t)]; N=[cos(a) sin(a)]; cFigure; hold on; hp1=plotV(vc,'b-','LineWidth',lineWidth); hp2=plotV(N,'k.','MarkerSize',markerSize); axis tight; axis equal; box on; grid on; view(2); set(gca,'FontSize',fontSize); legend([hp1 hp2],{'Circle boundary','Uniformly distributed points on circle'},'Location','NorthOutside'); drawnow;

* GIBBON* www.gibboncode.org

*Kevin Mattheus Moerman*, [email protected]

**GIBBON footer text**

License: https://github.com/gibbonCode/GIBBON/blob/master/LICENSE

GIBBON: The Geometry and Image-based Bioengineering add-On. A toolbox for image segmentation, image-based modeling, meshing, and finite element analysis.

Copyright (C) 2006-2021 Kevin Mattheus Moerman and the GIBBON contributors

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.