rstudio-education/primers

The learnr tutorials in RStudio Cloud's primers

primers's Issues

bind_rows behavior not as described

In 03-join-datasets.Rmd, the discussion of naming the source of data in bind_rows says, "bind_rows() will use the character string as the name of a new column that displays the name of the data set that each row comes from (as determined by the names in the list)." However, when I run:

bands <- list(df1 = band, 
              df2 = band2)

band %>% bind_rows(band2, .id = "origin")

the values in the column "origin" are "1" and "2", not (as I expected) "df1" and "df2".

Minor grammatical glitch

In 03-deriving.Rmd, "which take a vector of input" => "which take vectors as inputs" maybe?

Inconsistent capitalization in .Rmd filenames

some directories and files have all lowercase names (e.g., ./visualize-data/04-boxplots/04-boxplots.Rmd) while others have mixed case (e.g., ./tidy-data/01-Reshape-Data/01-Reshape-Data.Rmd). Is there a reason?

Advanced Control Flow in Write Functions Primer Broken

Clicking on the Advanced Control Flow link brings an error page. "The application failed to start (exited with code 1)."

The primer sounds interesting and I would love to practice!

Thanks.

Wrong starter code for line plot example?

In the first exercise for geom_line in 06-line-graphs.md, the starter code seems to be from the mpg dataset, and doesn't include a line plot, so I'm unclear why it's being provided.

Intermittently unable to start viewer

Using View() on the babynames tibble, I occasionally get the message below.

De-localize reference to Las Vegas

"functions are like Las Vegas" -> readers outside North America may not catch this (particularly if English isn't their first language)

Inconsistency in quoting named vectors

The first example of a named vector in 03-join-datasets.Rmd is c(uno = 1, dos = 2, tres = 3) without quotes around the names, but later examples doing joins quote the names. Quote the names here for consistency?

"Named list" is a bit of a jump

in 03-join-datasets.Rmd, "The easiest way to do this is to save the input data sets as a named list." seems a bit of a jump - the primer has introduced named vectors, but not named lists (or lists at all, really).

How can I tell that babynames is already a tibble?

in 01-tibbles.Rmd, "However, babynames is already a tibble" - should explain how I can tell.

01-Reshape-Data.Rmd ex13-solution y=total instead of y=n

babynames %>%
  group_by(year, sex) %>% 
  summarise(total = sum(n)) %>% 
  ggplot() +
    geom_line(aes(x= year, y= total, color = sex)) #total = sum(n)

Why does the readr logo show up in this diagram?

In 01-tibbles.Rmd, image transform-data/01-tibbles/www/images/tibble_display.png, why does the readr logo show up?

Blurry image

The text in visualize-data/01-bar-charts/www/images/positions.png is slightly blurry for me - is it possible to create an SVG version of this image?

Typo in tibbles primer (not in git)

Hey!

As I was reading through the primers on rstudio.cloud today, I noticed a typo. It seems that the typo was fixed in commit 712baa0. However this isn't reflected in the deployment on cloud (https://rstudio.cloud/learn/primers/2.1)

Multiple breakages in tutorials on writing functions

For the question "Use formals() to see the formal arguments of xor" in function-basics.Rmd, when I submit the answer, I get this complaint:

The same thing happens for the next question (about environment())

Duplicate serial number in visualize-data

visualize-data/ has both 01-Exploratory-Data-Analysis and 01-bar-charts - should the former not be 00?

Show current tutorial more clearly

As I work through the tutorials in a primer, it's sometimes hard to tell which one I'm in and which one is next. For example, this screenshot shows the menu when I've just started the tutorial on how to write a function - could that line in the drop-down be highlighted more clearly (I have old eyes), and/or could the title of the current tutorial show up in the menu bar?

Missing import in geom_hex exercise

Solution to this exercise is too big a jump

In list-columns.Rmd, I got to this:

Within mutate(), use a function that takes a list as input (models) and returns a double vector as output to place in coefficient. Don’t forget to actually provide models as an argument when you call the function.
Use the map expression ~coef(.x) %>% pluck("year") to populate coefficient with the year coefficients of each model.

and was lost - there's a lot going on in this all at once.

Clarifying behavior of separate function

Might be worth pointing out that sep = 1 in separate() splits after location 1, not from location 1 and forward (i.e., the indices are the top ends of ranges, not the starts).

Aesthetic mapping exercise 4 was completed immediately

I finished exercise 3 in the Aesthetic Mappings section of Data Visualization Basics and exercise 4 was presented to me but it was already completed.

Making navigation easier

I finish "tidyverse", and there's a button to go back to the previous topic, but how do I get to the next one in "Work with Data"? I can click on "Work with Data" to get the welcome page and then select "Isolating Data with dplyr", or click the hamburger menu and select it, but neither is immediately obvious.

First use of pmap should use named arguments

The discussion of pmap described the use of named arguments; the first example (ANOVA across three models) doesn't use them. Introduce another example that does to make the ramp a little gentler?

Shouldn't have to click "Try Again" after submitting wrong answer for MCQ

If I submit a wrong answer for an MCQ, I have to click "Try Again" before I can change my answer. It seems like I ought to be able to immediately select another radio button option and submit that without the extra step.

Dangling sentence

This package provides a shortcut for installing and loading the entire suite of packages in “the tidyverse”, e.g.

Dangling sentence in 01-tibbles.Rmd.

Odd formatting in 01-Reshape-Data.Rmd formulas

License for primers?

I'm in the process of developing materials for a data science class I will teach in fall. I would like to include parts of some of the primers in my exercises for students. Is such re-use and adaptation acceptable? I can't find the licensing conditions for the primers specified anywhere. Thanks!

Why is the section called "Isolating Data"?

Why is the section titled "Isolating Data"? Doesn't seem to connect with the content.

Strange quoted text output in 02-Vis-Basics

The following popped up as output for a question in 02-Vis-Basics - looks odd.

typo in isolating data with dplr primer

just starting w R and RStudio Cloud! Also new to github. So feel free to let me know how to do all this...

I found a small typo on the Isolating Data with dplyr primer.
The one_of example in the table is missing a closing parentheses. 😊
one_of() Columns whose name appear in the given set select(babynames, one_of(c("sex", "gender"))

They don't look like "two by two tables"

in 01-Reshape-Data.rmd, "cases, table4a, and table4b are all two by two tables" - those tables don't look 2x2 to me. Is this a statistical term I don't know?

Confusing wording

In 04-boxplots.Rmd, "Here each group functions like a vertical histogram." I would say that the output was a set of horizontal histograms.

I don't understand this sentence

in 01-Reshape-Data.Rmd: "Here the type column lists the keys" - what's a "type column"? The term doesn't seem to appear elsewhere in the primers.

Add primer on error handling

Add a section to the primer on testing that discusses error handling.

Explain multiple uses of `data` in solution

In list-columns.Rmd, the exercise that's introduced with "Add a new column to your data frame named models" has this as a solution:

nested_gapminder %>% mutate(models = map(data, ~lm(lifeExp ~ year, data = .x)))

It may be worth pointing out that the word data is being used in two different ways here.

duplicated problem statement in Programming Basics: Types

Statement is repeated: "One of the most common mistakes in R is to call an object when you mean to call a character string and vice versa."

"Continue" button does nothing

In "The history of your name" the Continue button doesn't do anything, but I was able to click "select()" in the menu on the left (image below)

?help doesn't bold text properly

When using ?help, the backspace characters used to add underlining/bold to text don't work, so the underscores are displayed:

Update .gitignore to ignore locally-generated .dcf files

After I previewed a tutorial locally (open .Rmd in RStudio 1.3, run tutorial), Git reported a new file tidy-data/01-Reshape-Data/rsconnect/shinyapps.io/gvwilson/01-reshape-data.dcf. I presume this shouldn't be checked into the repo - what change is needed to .gitignore? (There are lots of .dcf files in the repo, so I'm guessing *.dcf isn't the right answer.)

Loading with and without quotes

I load libraries using library(tidyverse) rather than library("tidyverse"); this tutorial tells me to do the latter and doesn't mention the former. Should it? Which is more common?

When will the "Coming Soon" primers be available?

The primer home page (https://rstudio.cloud/learn/primers) lists three primers as "Coming Soon." They are Report Reproducibly, Build Interactive Web Apps, and Organize Your Work. They look really good! Is there a schedule for when they might become available?

"select" should be "spread" on "Tidy Your Data" in "Reshape Data" first page

https://community.rstudio.com/t/select-should-be-spread-on-tidy-your-data-in-reshape-data-first-page/38645

What are model1 and model2?

In multiple-vectors.Rmd:

usa_mod1 <- model1 %>% pluck("United States")
usa_mod2 <- model2 %>% pluck("United States")

What are model1 and model2? I'm guessing from context that they are models based on year and (year + GDP per capita) but it would be helpful to re-create them here (since I made tea between doing the previous tutorial and this one and have forgotten).

use of 'lapply' without it being introduced

In introduction-to-iteration.Rmd, "R’s lapply family" -> lapply hasn't been introduced, so readers won't know what this refers to.

With the exception of ties

In 03-deriving.Rmd, "with the exception of ties, there was only one 1 in the entire data set, only one 2, and so on" - once ties are excluded, isn't there always one of each?

Why are we creating data.frames?

Why does the "Your turn" example use a data.frame instead of a tibble?

Show progress bars within sections

When working through the questions under any particular heading, I don't have any feeling for how much is left in the section. Some sort of progress bar showing how many sections or questions have been done/are left would be comforting.

Missing format description in exercise

In "Separate and Unite Columns", this exercise tells me to rewrite in the format below, but doesn't provide the format:

Why bother introducing dotplots given their shortcomings?

Dotplots are introduced, and then their shortcomings enumerated - given that this is a primer, not a reference, why bother introducing them at all?

Confusing exercise description

"Remember our steps" -> remember from where?

Combination of 1. and then a single sub-bullet.