convert cell array of mixed strings to cell array of numbers

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I have a cell array as follows:
ca = [{' [1000 X X X X]' } {' X' } {' X' } {' 1.234' }];
I would like to convert this into a numeric cell array where 'X' is interperted as 'NaN'. My solution uses the following function:
function out = x2decimal(in)
%sscanf doesn't handle NaN
X = NaN;
out = eval(in);
return
In cellfun:
out = cellfun(@(x) x2decimal(x), ca, 'Uni', false)
out = {1×5 double} {[NaN]} {[NaN]} {[1.2340]}
out{1} = 1000 NaN NaN NaN NaN
My solution works but contains the dreaded eval function. Do you see an alternative that is more mat-thonic?
On windows 10, matlab 2020b.
Thanks,
-Chris
  2 Comments
Dyuman Joshi
Dyuman Joshi on 8 Feb 2023
Not sure about mat-thonic, but here is another approach -
ca = [{' [1000 X X X X]' } {' X' } {' X' } {' 1.234' }];
ca = replace(ca,'X', 'NaN');
out = cellfun(@str2num, ca, 'uni', 0)
out = 1×4 cell array
{[1000 NaN NaN NaN NaN]} {[NaN]} {[NaN]} {[1.2340]}
checker
checker on 9 Feb 2023
Thanks, that saves me a custom function. Interestingly, str2num uses eval! I'd use str2double but want to perserve exactly the textual representation of the numbers (which are sourced from a single precision float) and it's not clear to me how str2double would affect the display.

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Answers (1)

Stephen23
Stephen23 on 9 Feb 2023
Edited: Stephen23 on 9 Feb 2023
ca = {' [1000 X X X X]', ' X', ' X', ' 1.234' }
ca = 1×4 cell array
{' [1000 X X X X]'} {' X'} {' X'} {' 1.234'}
out = regexp(ca,'[^\s\[\]]+','match');
out = cellfun(@str2double,out,'uni',0)
out = 1×4 cell array
{[1000 NaN NaN NaN NaN]} {[NaN]} {[NaN]} {[1.2340]}
  2 Comments
Dyuman Joshi
Dyuman Joshi on 9 Feb 2023
So the approach above is to divide each element into cell arrays and then use str2double?
Stephen23
Stephen23 on 9 Feb 2023
"So the approach above is to divide each element into cell arrays and then use str2double?"
Yes.

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