convert values to string

I have a vector with values to define groups (groupValue, in this case 1000x1 array with values from 1 to 5) I also have a cell array with strings for each of these values (labels, 5x1 cell array) I want to have a 1000x1 cell array with strings for the labels instead of values. How can I do this more efficiently i.e. without a for loop?

for kk = 1:nElements
    groupLabels{kk} = labels{groupValue(kk)};
end

Answer 1

[Guillaume]

Simply,

groupLabels = labels(groupValue);

[Ingrid]

when I tried this directly (I first tried to do the assignment of the labels to the data directly with indexing larger than threshold values) and then it gave me warnings of improper assignments and dimensions that did not correspond. So I had no clue that in this form it was possible.

[Guillaume]

Yes, for this to work groupValue must be integers between 1 and numel(labels). You could precede the above line with:

validateattributes(groupValue, {'numeric'}, {'positive', 'integer', '<=', numel(labels)}, '', 'groupValue'};

Answer 2

[Geoff Hayes]

Ingrid - if labels is your cell array of string labels and groupValue is your integer array of group values (or indices into labels) then perhaps you could try something like

 groupLabels = labels(groupValue);

Answer 3

[Renato Agurto]

hello. This should work

 groupLabels = labels(groupValue);