Machine Learning with R Cookbook - Second Edition

How to do it...

Perform the following steps to convert the types of character variables:

1. Assign the airquality dataset to mydata:

        > mydata <- airquality  

2. To transform the variable from the int numeric type to the factor categorical type, you can cast factor:

        > mydata$Month = factor(mydata$Month)  

3. Print out the variable with the str function and again, you can see that Month is now transformed into the factor as follows:

        > str(mydata)        Output        'data.frame': 153 obs. of 6 variables:$ Ozone :         int 41 36 12 18 NA 28 23 19 8 NA ...         $ Solar.R: int 190 118 149 313 NA NA 299        99 19 194 ...         $ Wind : num 7.4 8 12.6 11.5 14.3 14.9 8.6 13.8         20.1 8.6 ...         $ Temp : int 67 72 74 62 56 66 65 59 61 69 ... $ Month : Factor w/ 5 levels "5","6","7","8",..: ...