Data frames in R - Transforming data PART I

Key Takeaways

hello and welcome back to our first attest Excel data science in the next few lessons we will dive deep into the Star Wars data and we'll learn how to transform data sets in various creative and not so creative ways let's get to it this is the first real lesson in which we will use the deployer package for the distracted souls out there the player is part of the tidy verse and we got it when we install the tie diverse ecosystem of packages it specializes in data manipulation tools that deal with filtering mutating and summarizing data first things first let's fire up the Star Wars data frame that comes with deep liar this time I will save it as Star notice that the Digga are saved as a table instead of on our based data frame let's keep it this way and use some of the table properties tables come in handy here because this is a relatively big data set and we don't want to see the entire thing every time we do an operation and print to see our results tables limit the printing to just a few rows okay although we've already looked at it before if you want to see the data in all of its glory run view star this will open the viewer and you can scroll through the values to your heart's content right transforming data the filter function does what we think it does subsets data according to a set of criteria it looks like this we pass the data and then the expression according to which we want our data filtered there can be more than one criteria of course for instance I can select all the droids in the data frame and now I can only call on the ones from Tatooine right yes that makes sense it was young Anakin Skywalker who rebuilt c-3po while still on Tatooine and our 5d for well I'm not sure I know anything about that little r5 unit okay filter also works with logical operators so for example I can call every character that has red orange or yellow as an eye color okay the majority of these aren't human hmm I wonder if there are any more humans with weird eyes apart from Darth Vader and Palpatine No yikes alright next we have the Select function now our database may not have hundreds of variables but looking at the column names it does feel like I genuinely don't need to know about some of these things to narrow down the data to the information I want I can use select this selects specific individual columns by name if I want to select the column and then everything between two other columns I can do this isn't this already a lot easier to do than with the base our functions we learned earlier hmm it is but check this out to select works nicely with a couple of nifty functions like starts with or ends with which let us subset data in a super intuitive way so if I wanted to get all the columns that have to do with coloration I can run this okay new scenario there are a bunch of interesting variables you want to look at but you also don't want to ignore the rest of the data what do you do well you can use the everything function with select to move the variables you want to the beginning of the table and then show everything else like this sweet right finally let's look at the mutate function mutate is the pliers easy way of creating new variables from variables that already exist in the data set for example I can calculate the BMI for our characters because the starwars data has recorded both height and mass information you of course this is largely uninformative because the BMI scale is extremely human centered but you know anything to get the point across now if mutate is the function to use when you want to add a column to your data while also retaining all the other columns in your data frame then transmute is what you will opt for if you only want to keep the variable you create let me show you what I mean see effectively transmitted created my new variable and allowed me to extract it without tagging everything else along as well fantastic ok I will win this lesson here because otherwise I'm at risk of going into way too much detail about side comments I make so thanks for watching everyone and in the next lesson we will pick it right where we left off see you there for more videos like this one please subscribe