Add rows to a table in a parfor loop
10 views (last 30 days)
Show older comments
Hi,
I'm trying to add a row to a Table inside each iteration of a parfor loop, simplified would be something like this:
T=table;
base='/Volumes/Cortegada/AUDIOS'; %Base directory of the audios to read an process
for m=1:length(months)
days=dir(strcat(base,months{m}));
days=days(3:end-1);%
for d=1:length(days)
files=dir(strcat(base,months{m},'/',days(d).name,'/*.wav'));
parfor f=1:length(files)
%Each month and day folder has a different number of files
[x,fs]=audioread(strcat(base,months{m},'/',days(d).name,'/',files(f).name));
%% Some processing with some OUTPUTVARIABLES
temp=table(OUTPUTVARIABLES);
T=[T;temp];
end
end
end
save('T.mat','T');
But it gives me the error:
{ Error using table (line 245)
Transparency violation error.
See Parallel Computing Toolbox documentation about Transparency
}
Any clues on how to solve it? I can accessto the exact table position because there each month/day folder has a different number of audio files
All the best
0 Comments
Answers (1)
Edric Ellis
on 14 Apr 2021
Edited: Edric Ellis
on 16 Apr 2021
This problem should have been fixed in R2019b (please let me know if you're using a later version and things are not working). It might work to explicitly specify the 'VariableNames' for your table, like this:
T = table();
parfor i = 1:4
p = rand(); q = datetime();
temp = table(p,q,'VariableNames', {'p', 'q'});
T = [T; temp];
end
disp(T)
3 Comments
Edric Ellis
on 16 Apr 2021
It might be better still to preallocate the table to the correct size, i.e.
T = table(zeros(totalRows,1), zeros(totalRows,1), 'VariableNames', {'p', 'q'})
See Also
Categories
Find more on Data Type Identification in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!