using accumarray to combine text

Hi,

I am trying to use accumarray to concatenate string.

tdata = table([ 1 2 2 3 4 2]', ["a","b","c","d","e","f"]', 'VariableNames',{'EBID','Name'});
[uniqEBID,~,JGrp] = unique( tdata(:, {'EBID'}));
joinStr = @(tStr) { sprintf([repmat('%s|| ', 1, length( tStr)-1) '%s'], string( tStr))};
joinStr( tdata.Name) % anonymous function seems to do the job

However when running script below, i got error message

accumarray( JGrp,  tdata.Name, [], joinStr)

Error using accumarray

Second input VAL must be a full numeric, logical, or char vector or scalar.

Answer 1

[_]

Does this do what you want?

tdata = table([ 1 2 2 3 4 2]', ["a","b","c","d","e","f"]', 'VariableNames',{'EBID','Name'});
[uniqEBID,~,JGrp] = unique( tdata(:, {'EBID'}));
joinStr = @(tStr) { sprintf([repmat('%s|| ', 1, length( tStr)-1) '%s'], string( tStr))};
% joinStr( tdata.Name) % anonymous function seems to do the job
joinStr( tdata.Name(JGrp))

ans = 1×1 cell array
    {'a|| b|| b|| c|| d|| b'}