How to check if an entire column of string variables can potentially be converted to numerical values?

1 vue (au cours des 30 derniers jours)
I have a column variable normally look like this:
'ABC1234'
'DEC1236'
'CFG5645'
...
Once in a while the column data will be like this, i.e., composed entiredly of strings that can be converted to numerical values.
'1234567'
'2312456'
'7863522'
...
When this happens, I want to use str2num to convert them into numerical values first before using writetable to put them into an Excel file. Otherwise, I would see all those yellow diamonds with ! inside next to each row of the column to indicate errors.
So how do I detect if all elements in an entire column can potentially be converted to numerical values?
Also when I treid to use str2num, why am I getting the below error?
Input must be a character vector or string scalar.
  3 commentaires
Leon
Leon le 17 Oct 2019
Cool. It works! I did not know there is a str2double() before.
Thank you so much.
Guillaume
Guillaume le 17 Oct 2019
Modifié(e) : Guillaume le 17 Oct 2019
As the documentation of str2num states, it's a dangerous function to use (internally it uses eval so I could give you a string that would delete everything on your hard drive were you to pass it to str2num.)
Whenever possible prefer str2double which is guaranteed to not have any side effect.

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Réponse acceptée

Matt J
Matt J le 18 Oct 2019
~any(isletter(yourMatrix(:)))
  2 commentaires
Guillaume
Guillaume le 18 Oct 2019
Performing the conversion and checking for NaNs would be more reliable. The above would be happy with '------' which is of course not a valid number.
Leon
Leon le 18 Oct 2019
Modifié(e) : Leon le 18 Oct 2019
Many thanks, Everyone, for your help!

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Plus de réponses (1)

Matt J
Matt J le 18 Oct 2019
all(48<=yourMatrix(:) & yourMatrix(:)<=57)

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