# How can a 4 element array index pull stored string values?

4 views (last 30 days)
Akana Juliet on 18 Jun 2021
Commented: Akana Juliet on 18 Jun 2021
Hi all, I am new to MATLAB and I'm a bit stuck trying to figure out this part.
Let's say I have a 4 element vector [1x4 double] stored called "fourElementVector" (I have a function that changes these numbers a bit, situationally)
I also have a 256x1 cell "HexData" that stores a bunch of hexadecimal strings (ranging from 16bit to 128bit)
I'm trying to make the fourElementVector be the index and pull the values stored in HexData and store them as a string like:
[0B287 0B287 0B287 0B287] (just for an example. I don't want them converted)
The 4vector will always have a stored index numbers ranging from 1 - 256, and I have 256 hex codes, so it matches.
What do you think? How might I achieve this?

Scott MacKenzie on 18 Jun 2021
Edited: Scott MacKenzie on 18 Jun 2021
I think this is more or less what you are after. The output is generated both as a cell array and as a string vector.
% create random 16-bit hex values (as strings)
h = '0123456789abcdef'
idx = randi([1 16], 256, 4);
hexDataChar = h(idx);
% convert to 256x1 cell array of hex values
hexData = cellstr(hexDataChar);
% four element vector of indices
idx = randi([1 256], 1, 4);
% get four hex values from cell array
result1 = hexData(idx)
result2 = string(result1)
Output:
result1 =
4×1 cell array
{'b349'}
{'9cb2'}
{'cf42'}
{'1205'}
result2 =
4×1 string array
"b349"
"9cb2"
"cf42"
"1205"
Akana Juliet on 18 Jun 2021
Thank you so much!

### More Answers (1)

the cyclist on 18 Jun 2021
Can you upload examples of your variables fourElementVector and HexData, in a MAT file? This would be helpful.
But it seems from your description that
HexData{fourElementVector}
might do what you intend?
Akana Juliet on 18 Jun 2021
Thank you so much! I think I got it. Next time I'll share a bit more though!

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