I have some healthcare data and need to find key value pairs from this data set. I have pre processed the data (i.e. remove stopwords , stemming etc. ) and it looks something like this : 1. chest clear 2. chest b lclear 3. chest pt incent spirometri 4. chest nad 5. pain left chest 6. symptomat chest tight increas 10 --- Now I want to find the value of key "chest" from this type of set (e.g. clear , nad , pain etc.). How can I do this. You can assume keys are known are suggest a method to find the keys also. This is just an example of large data set. I am using R language. Thank you in advance
