filling blanks with NA

I do have a data set with some missing values that appear as blanks. I 

want

to fill these  blanks with an NA. How can this be done? Thanks for your 

help

Please help us to help you.  What form are the data in?  Are they in a 
text file, or are they in R already?  What do you mean by 'blanks'?  If we 
can reproduce your problem then we can solve it more easily.

Regards,
Richie.

Mathematical Sciences Unit
HSL


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