Experiment with a random presentation of images from a folder

7 次查看（过去 30 天）
Clarissa
Clarissa 2022-10-16
评论： Clarissa 2022-10-17
Hi everyone, I'm new to matlab. I am trying to create a script for my experiment. The script should consist in the presentation on the screen of 40 images showing emotional faces (with 3 different emotions: neutral, happy, angry) from a folder called "images.experiment". These images must be presented randomly without repeating themselves in a loop which is repeated 3 times. After each image I should make an assessment of the intensity ("how emotional is the stimulus you see?") of the emotion in the image on a Likert scale from 1 to 9. Finally I have to save every answer (according to the condition/image) of each subject on an excel document. Can someone help me? I am using Psychtoolbox on Window. Thanks everyone in advance.
  4 个评论
显示 2更早的评论
Walter Roberson
Walter Roberson 2022-10-16
randperm(40) three times to get the order of presentation. The rest about showing an image at a particular location for a particular time is really psychtoolbox functions not MATLAB. Functions to get input with timing is also psychtoolbox

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2022-10-16
移动：Walter Roberson 2022-10-16
http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F shows how you can read a series of files. assign them into a cell array. Then
numfiles = numel(YourCellArray);
order_to_show = [randperm(numfiles), randperm(numfiles), randperm(numfiles)];
Now do whatever psychtoolbox requires you to do in order to set up the screen. Then you would do something similar to
for K = 1 : numel(order_to_show)
this_image = YourCellArray{order_to_show(K)};
do whatever psychtoolbox needs to present the fixation point for the given time
do whatever psychtoolbox needs to present this_image for the given time
do whatever psychtoolbox needs to present the mask for the given time
do whatever psychtoolbox needs to retrieve the user input
responses(K) = user response
end
results = table(order_to_show(:), responses(:), 'VariableNames', {'ImageNumber', 'Response'});
writetable(results, 'FileNameToWriteTo.xlsx');
You might modify the results table slightly if you wanted to write in the image name instead of the image number (index), something like
results = table(ImageNames(order_to_show(:)), responses(:), 'VariableNames', {'ImageName', 'Response'});
  3 个评论
显示 1更早的评论
Walter Roberson
Walter Roberson 2022-10-16
All the details about presenting for a given time or fetching user input, are using Psychtoolbox supplied functions. Psychtoolbox has its own support forum. The details are not really appropriate here since they are third-party functions not supplied as part of Mathworks products.
See https://www.mathworks.com/matlabcentral/answers/143088-real-time-detect-keypress#answer_285124 for information about the input options.
Clarissa
Clarissa 2022-10-17
try
Screen('Preference', 'SkipSyncTests', 1);
% Open window with default settings:
myWindow=Screen('OpenWindow', 0, 127);
% Specify the folder where the files live.
myFolder = 'C:\Users\clari\OneDrive\Desktop\MATLAB\im.prova';
% Check to make sure that folder actually exists. Warn user if it doesn't.
if ~isfolder(myFolder)
errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
uiwait(warndlg(errorMessage));
myFolder = uigetdir(); % Ask for a new one.
if myFolder == 0
% User clicked Cancel
return;
end
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.png'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
for k = 1 : length(theFiles)
baseFileName = theFiles(k).name;
fullFileName = fullfile(theFiles(k).folder, baseFileName);
fprintf(1, 'Now reading %s\n', fullFileName);
% Now do whatever you want with this file name,
% such as reading it in as an image array with imread()
imageArray = imread(fullFileName);
imshow(imageArray); % Display image.
drawnow; % Force display to update immediately.
end
numfiles = numel(imageArray);
order_to_show = [randperm(numfiles), randperm(numfiles), randperm(numfiles)];
for K = 1 : numel(order_to_show)
this_image = imageArray(order_to_show(K));
texture(K)=Screen('MakeTexture',myWindow,this_image);
end
for K= 1:numel(order_to_show)
Screen('DrawTexture',myWindow,texture(K))
Screen('Flip',myWindow);
%wait
WaitSecs(0.2)
end
%close the screen
sca;
catch
%#ok<*CTCH>
% This "catch" section executes in case of an error in the "try"
% section []
% above. Importantly, it closes the onscreen window if it's open.
sca;
fclose('all');
psychrethrow(psychlasterror);
end
I'm tryng doing this but it doesn't work and when I run this, MATLAB crashes completely

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Image display and manipulation 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by