# Concentric Rings / Radial Sine Grating **URL:** \ **Category:** Programming Help\ **Created:** [April 3, 2024, 12:33pm UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321 "2024-04-03T12:33:39Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![leonardo](https://avatars.discourse-cdn.com/v4/letter/l/e56c9b/32.png) [@leonardo](https://psychtoolbox.discourse.group/u/leonardo)\ **Post date:** [April 3, 2024, 12:33pm UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321/1 "2024-04-03T12:33:39Z")
Hi all, I’m new to MATLAB and Psychtoolbox. I am currently trying to create concentric rings moving inward (with different contrast) for a task. I’ve seen a specific function with python that creates this (there seems to be none in MATLAB?). Saw a couple of papers that managed to create this using Psychtoolbox but still could not figure out how. Would very much appreciate any help I can get! ![Picture1](https://global.discourse-cdn.com/free1/uploads/psychtoolbox/original/1X/35fa013ffff50eae457096f8f8272dc1fff01abb.png) ---
**Author:** ![\_qx1147](https://avatars.discourse-cdn.com/v4/letter/_/a8b319/32.png) [@\_qx1147](https://psychtoolbox.discourse.group/u/_qx1147)\ **Post date:** [April 3, 2024, 5:57pm UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321/2 "2024-04-03T17:57:48Z")
Have you looked at ExpandingRingsDemo.m? ---
**Author:** ![leonardo](https://avatars.discourse-cdn.com/v4/letter/l/e56c9b/32.png) [@leonardo](https://psychtoolbox.discourse.group/u/leonardo)\ **Post date:** [April 4, 2024, 6:06pm UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321/3 "2024-04-04T18:06:56Z")
Just did, thank you! Though it might not be what i’m looking for, it’s closer to what I want to make. Also found the “Radial Checkerboard Demo” and managed to create a static concentric ring in the middle. Might look into both of them further. Thanks again! ---
**Author:** ![pscarfe](https://avatars.discourse-cdn.com/v4/letter/p/e8c25b/32.png) [@pscarfe](https://psychtoolbox.discourse.group/u/pscarfe)\ **Post date:** [April 10, 2024, 11:06am UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321/4 "2024-04-10T11:06:43Z")
> [@\_qx1147](#): > > ExpandingRingsDemo Expanding rings demos is the way to go. My Radial Checkerboard Demo is not really designed to be dynamic in the way you need. ---
**Author:** ![leonardo](https://avatars.discourse-cdn.com/v4/letter/l/e56c9b/32.png) [@leonardo](https://psychtoolbox.discourse.group/u/leonardo)\ **Post date:** [April 10, 2024, 3:40pm UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321/5 "2024-04-10T15:40:24Z")
Thank you! I’ll be sure to work based on the ExpandingRingsDemo. ---
**Author:** ![Ian-Max-Andolina](https://yyz2.discourse-cdn.com/free1/user_avatar/psychtoolbox.discourse.group/ian-max-andolina/32/4_2.png) [@Ian-Max-Andolina](https://psychtoolbox.discourse.group/u/Ian-Max-Andolina)\ **Post date:** [April 12, 2024, 6:12am UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321/6 "2024-04-12T06:12:02Z")
I have some procedural (like ExpandingRingsDemo) grating shaders that do polar + radial + spiral square or sine gratings that can be animated: > [@How to create bullseye stimuli in PTB?](https://psychtoolbox.discourse.group/t/how-to-create-bullseye-stimuli-in-ptb/3915): > > Hi all! This is Jiangang. I’m trying to use bullseye stimuli (sine-wave concentric circles with parameters like contrast and spatial frequency, similar to gratings) in my experiment. Just like what is shown in fig. 1 of this study ([Dynamic hidden states underlying working-memory-guided behavior | Nature Neuroscience](https://www.nature.com/articles/nn.4546)). It has been done with Psychtoolbox but I cannot find how it is done anyhow. Any help would be much appreciated! Jiangang UW-Madison ---
**Author:** ![leonardo](https://avatars.discourse-cdn.com/v4/letter/l/e56c9b/32.png) [@leonardo](https://psychtoolbox.discourse.group/u/leonardo)\ **Post date:** [April 12, 2024, 3:45pm UTC](https://psychtoolbox.discourse.group/t/concentric-rings-radial-sine-grating/5321/7 "2024-04-12T15:45:30Z")
Exactly the way I wanted it, thank you!