1. When making a data frame, it is important to specify stringAsFactors to be false so that R doesn't covert incorrect info into strings and run without an error/warning.

Functions:

2. grep

• grep(column grep needs to be applied to, pattern = "[]")
• grep(myIDs$name, pattern = "^[0-9]")
• NOTE: the hat sign outside means starts with
• hat sign inside the brackets means not

3. is.na()

• Checks to see if the values in the vector are na
• true if it is na

4. Creating a new row

• dataframeName$newColName <- calculate the column

5. strsplit

• unlist(strsplit(stringToBeSplit, "splitbywhat"))
• unlist(strsplit(seq,""))
• can operate on lists and value which is why unlist is nessasary

6. rbind

• adds a data frame to an already existing data Frame
• df <- rbind(df, writeTheAdditionalDataFrame)

7. unique

• returns the unique values in the column
• unique(colName)

8. gsub

• varnameNew <- gsub("[^A-Za-z]", "", varname)
• "[^A-Za-z] means what should be substituted
• varname is which variable needs to be substituted
• varnameNew is the name of the new variable where we are storing the substituted value

RegEx:

Taken from

Cleaning R-History:

• Open terminal
• rm .Rhistory