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Exercise

Dealing with missing values

Missing values are often encoded differently. In some files, -9999 mean missing values and in others, they may be encoded as #$##. You can use the na.strings argument to tell fread() which values should be treated as missing values.

You will be importing the following file: 

id,name,val1,val2
9002019291929192,Robert Whitaker,,44
9200129401349301 ,Elisa Waters,289,##
9200149429834456 , Karla Schmidt,458,29

The missing values are encoded as "##". Note that fread() handles an empty field ,, by default as NA.

Instructions

100 XP

Import the file sample.csv properly to ensure that "##" is treated as a missing values and is imported as NA.