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How to access a string array and use the contents as titles within array2table

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Meancoh is an 24x6 ordinary array.
meancoh=zeros(TT2,n1);
I've created a 6x1 string array called storehere, that, if accessed, contains the following:
"mean of bootstrapped coherence between X and Y"
"mean of bootstrapped coherence between X and Y"
"mean of bootstrapped coherence between X and Y"
"mean of bootstrapped coherence between X and Y"
"mean of bootstrapped coherence between X and Y"
"mean of bootstrapped coherence between X and Y"
Now, I think I ought to use array2table to assign the 6 rows above to each of the 6 columns of data in meancoh. I've tried but I don't seem to get it right.
Any suggestions?
P.S.
I asked a question relating to a previous problem (i.e. how to create storehere), which I cancelled once I realised I was just missing a bracket. I didn't realise someone had already commented-I saw an email to that effect just after, with a comment from 'the cyclist'. I apologise, as I didn't see someone had already made an effort to answer. The lines below work. I was missing a smooth bracket in the loop.
Now I have a string array called nameVar that contains this:
x y
x v
x z
y v
y z
v z
Fine. Now I need to create 6x1 string array that in which each row says ‘mean of bootstrapped coherence between (:) and (:).
This doesn’t work:
storehere=strings(Nrowscombinations,1);
for kkk=1:length(Nrowscombinations)
storehere(:)=strcat({'mean of bootstrapped coherence between '}, nameVar(kkk,1),{ ' and ' }, nameVar(kkk,2));
end

Accepted Answer

Guillaume
Guillaume on 28 Nov 2018
I would create your storehere array, this way:
storehere = compose("mean of bootstrapped coherence between %s and %s", nchoosek(["X", "Y", "V", "Z"], 2))
However, there is absolutely no way that you can use these strings as variable names in a table. Table variable names, like all matlab variable names have some restrictions on which characters are allowed. In particular, spaces are not allowed.
You could use matlab.lang.makeValidName to make valid variable names out of your string array. It will remove the spaces, or you could replace the spaces by _:
array2table(meancoh, 'VariableNames', matlab.lang.makeValidName(storehere))
%or
array2table(meancoh, 'VariableNames', strrep(storehere, ' ', '_'))
However, I would recommend that you use shorter variable names altogether.
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More Answers (1)

Peter Perkins
Peter Perkins on 28 Nov 2018
It's not really clear what you are doing and what went wrong. If your matrix of data has 6 columns, then array2table will accept a 6-element string array or cell array of char rows as the variable names. And you'r problem is how to create those names?
For one thing, the names have to be valid MATLAB identifiers, and unique. I'm gonna suggest that you name the variables "x_y", "x_v", etc., and set the VariableDescriptions property of the table to "mean of bootstrapped coherence between x and y", etc. I imagine something like this
>> namevar = ["x" "y"; "x" "z"; "y" "z"]
namevar =
3×2 string array
"x" "y"
"x" "z"
"y" "z"
>> "mean of bootstrapped coherence between " + namevar(:,1) + " and " + namevar(:,2)
ans =
3×1 string array
"mean of bootstrapped coherence between x and y"
"mean of bootstrapped coherence between x and z"
"mean of bootstrapped coherence between y and z"
is what you need.
  1 Comment
Fede C 2018 London
Fede C 2018 London on 28 Nov 2018
I don't know how I didn't see that the way I wrote the loop to fill up 'storehere' was wrong.
Based on what you said above, this:
for kkk=1:length(Nrowscombinations)
storehere(:)="mean of bootstrapped coherence between " + nameVar(:,1) + " and " + nameVar(:,2);
end
does the trick. storehere is a 6x1 string array:
"mean of bootstrapped coherence between X and Y"
"mean of bootstrapped coherence between X and V"
"mean of bootstrapped coherence between X and Z"
"mean of bootstrapped coherence between Y and V"
"mean of bootstrapped coherence between Y and Z"
"mean of bootstrapped coherence between V and Z"
My question is how do I tell array2table to accept the strings in storehere as the valid variable names?

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