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I have a problem with the follwoing error message

invalid regular expression '([a-Z]*)_(.*)', reason 'Invalid character range'

so the line of code which causes the error is 

if(tide=="long") names(problem) <- sub("([a-Z]*)_(.*)","\\2",problem)

so if long is selected for the parameter tide in the function the names of problem shall be defined ....

but when I enter function(...,tide="long",..) the above mentioned error message is displayed.

stema
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Tim Heinert
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2 Answers2

6

You can't use [a-Z], because the letters are in the wrong order, but anyway it is better to use: 

[a-zA-Z]

The problem is that those ranges are based on tables (either ASCII or Unicode), but the uppercase letter "Z" comes before the lowercase letter "a" so the range is in the wrong order.

The other solution to use [A-z] would be a valid range, but there are the characters 

[\]^_`

between the letter "Z" and the letter "a", so this range would include characters that you normally don't want to match.

stema
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0

Your problem is this [a-Z]

You have to write either : [a-z] or [a-zA-Z]

Oussama Jilal
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