Hi Brian! Thank you for your question, that's very interesting! We'll discuss this in our live session this week, stay tuned!

Hi Brian! I recorded a quick video to show how you could deal with this. Hope it helps!

Perfect

Hey! =D The short answer is: you shouldn't do that! There are some complicated workarounds, but by default, you should make it explicit in your code when NAs are being ignored/dropped. We'll discuss this on Thursday too!

Hey, Rachel! Here are some answers for you:

Q: Why is it required to use the summarize() function before using the more specific summary functions (e.g., mean())?

A: summarize() is allowing you to create/name a column in a data frame or tibble that will contain your summary value (like your mean). You could run mean directly on your column and it would output just a value, not a data frame or tibble with a named column.

For example, if you ran:

tomatoes |>
    drop_na(productionvalue) |> 
    pull(productionvalue) |> 
    mean()

You'd get a single value as your output:

[1] 3816933

If you use summarize, like this:

tomatoes |>
    drop_na(productionvalue) |> 
    summarize(meanvalue = mean(productionvalue))

You'd get a tibble that looks like this:

# A tibble: 1 × 1
  meanvalue
      <dbl>
1  3816933.

Of course, it's more helpful when you're adding a mean column to a grouped data set so that your resulting data frame has a row for each group containing the group name and the group's mean. I hope this helps!

Q: Does the "rm" in "na.rm" stand for anything? Just asking as it might help me remember that argument if so.

A: Yep! It stands for "remove" so you can say "na remove" in your mind to help remember it.

Thanks Libby, this is really helpful!

I was curious about Rachel's Q1 as well! Thanks for asking, Rachel, and for your response, Libby.

Hmm, hard to say. Can you please post your full code so I can run it and check what might be going on?

Hey, Maria! Just wanted to contribute my experience here: sometimes this happens to me when I use summarize and I don't know why, but if I restart R (Session > Restart R) it goes away and works fine! When in doubt, restart R 😅 Let us know if it works and share your code so we can see what you were running!

Thank you! I found out what the issue was... I changed it to summarise() and it worked! so strange...

This same thing happened to me, too. I figured out that it's because there is a function called "summarize" in the package "dataReporter" which David talks about in Week 1. For my work in Week 2, I just went ahead and loaded all of the packages I used in Week 1 (including dataReporter) before completing the exercises, and I got the same output as Maria Montenegro. If I don't load dataReporter, it works fine and gives me the mean. There is a warning message about dataReporter masking summarize from dplyr, but it's easy to miss if you're moving quickly. dataReporter doesn't contain a function called "summarise", so if you're using the English spelling, you don't run into this problem.

Good observation, Sara! One way to go around it is to explicit which package your function is coming from, using the double colon notation. dplyr::summarize() will return one type of results, and dataReporter::summarize() will return another type of results.

You can play with the code below to check the difference yourself:

library(dplyr)
library(dataReporter)
library(palmerpenguins)

penguins |> 
dplyr::summarize( 
  mean_bill_length_mm = mean(bill_length_mm)
)

penguins |> 
  dataReporter::summarize( 
    mean_bill_length_mm = mean(bill_length_mm)
  )

Oh thanks! Throughout my haphazard, self-guided journey of learning R, I have always wondered why sometimes code lists the "package::" before the function.The pieces of the puzzle are coming together for me now :)

That's a perfectly good way to write code!

thank you

oh i just realized it doesnt shows the output; it is this for both codes:

It's hard to know exactly what's going on because I can't see your code all the way from when you imported the data, but my guess is that you removed the NAs prior to running the summarize() function. If you do this (e.g. with the drop_na() function), then summarize() will work fine without the na.rm argument.

Hi Myles! I can't reproduce your error. The possibilities that I can think of are that you have a package loaded with a similar function that is overwriting the dplyr summarise function, or there is a typo in your code somewhere... Restarting the session might help in this case!

Do you wanna share more details about your script?

Yes, this is an example of a code I enter:

# Load Packages -----------------------------------------------------------

# Load the tidyverse package

library(tidyverse)

# Import Data -------------------------------------------------------------

# Download data from https://rfor.us/penguins
# Copy the data into the RStudio project
# Create a new R script file and add code to import your data

penguins <- read_csv("penguins_data.csv")

# Calculate the weight of the heaviest penguin.
# Don't forget to drop NAs!

penguins |> 
  summarize(max_body_mass = max(body_mass_g))

I restarted R studio and it worked! Thank you

Amazing! Sometimes that's all it takes! 😁