Changes

Neurobs Presentation

152 bytes added, 09:36, 18 January 2016
no edit summary
== General =={{see also|Presentation (www.neurobs.com) is a MS Windows based programming tool that allows experimenters to set up and program all sort of experiments. It is the recommended software for time-accurate experiments and therefore supported by the institutes’ (Social Sciences Faculty, the MPI and the Donders Centre for Cognitive Neuroimaging) technical groups.The technical groups offer (PhD) students a couple of preprogrammed experiments (i.e. templates), which can be adjusted to build up own experiments. In this way, the (PhD) student can efficiently program experiments fitting an technical optimal environment.}}This is what this course is all about. It aims at teaching programming skills, which are needed to modify the existing templates such that they meet your own demands. Because this can be quite complex, page documents some bugs we start with short assignments, which address one basic and simple problem at a timeencountered in Presentation. They will all contribute Users should go to the final assignment in which you will work on an existing template.== Course ==Find the presentation workshop documentation here [[Media:Programming with Presentation_2013.pdfPresentation]]page.
Find == Screen synchronization issue on 120 Hz screens ==There is a serious synchronization issue where the presentation prereader here [[Mediapicture.present() method returns one frame too early. It can be detected by measuring the time between two consecutive present() calls returning:presentation pcl pre-read_2013_.pdf]]
<pre>wait_interval(220);picture1.present();int t0 =clock.time(); picture2.present();int t1 = Template =clock.time(); int dt =t1-t0;Find the presentation Template here [[Media:Template2014.zip]]</pre>
One would expect ''picture1'' to be shown for 1 frame (1/120 s) and time ''dt'' to show this. Sometimes this is not the case. The image will be shown for one frame (1/120 s), but ''dt'' will be 2/120 s: [[File:Timeline.svg|400px|none|synchronization bug timeline]] The fact that ''picture1'' is shown for only 1/120 s was confirmed with a light sensor connected to an oscilloscope. The chance of this issue occurring is highly dependent on the waiting time prior to the first ''present()'' call: [[File:Occurrence.png|400px|none|synchronization bug occurrence]] Neurobs people seem to [http://www.neurobs.com/menu_support/menu_forums/view_thread?id=9463&expand_all= Other Templates 1 think] it has something to do with triple buffering, but the graph above was created without triple buffering enabled.[[File:Failsync2.png|none|Difference of arrival times of two consecutive markers (no red bars are hidden)]] <!--==References==<references/>-->