swirldev/swirl_courses

:mortar_board: A collection of interactive courses for the swirl R package.

swirl courses

This is a collection of interactive courses for use with the swirl R package. You'll find instructions for installing courses further down on this page. Some courses are still in development and we'd love to hear any suggestions you have as you work through them.

For more information regarding swirl, visit swirlstats.com or the swirl GitHub repository. If you'd like to write your own interactive content, please visit the Instructors page of our website.

Here are our current offerings, organized by level of difficulty:

Beginner

• R Programming: The basics of programming in R
• R Programming E: Same as the original, but modified slightly for in-class use (see below ***)
• The R Programming Environment

*** R Programming E is identical to R Programming, except we've eliminated the prompts for Coursera credentials at the end of each lesson and instead give students the option to send an email to their instructor notifying them of completion. Admittedly, it's sort of a hack until we come up with a more robust solution for in-class use (i.e. an instructor "dashboard").

Intermediate

• Regression Models: The basics of regression modeling in R
• Getting and Cleaning Data: dplyr, tidyr, lubridate, oh my!

Advanced

• Statistical Inference: This intermediate to advanced level course closely follows the Statistical Inference course of the Johns Hopkins Data Science Specialization on Coursera. It introduces the student to basic concepts of statistical inference including probability, hypothesis testing, confidence intervals and p-values. It concludes with an initiation to topics of particular relevance to big data, issues of multiple testing and resampling.
• Advanced R Programming

Since our users come from a variety backgrounds, it's very hard to label material as Beginner, Intermediate, or Advanced. If you find something that is labelled Beginner to be challenging, please don't be discouraged. The first step of learning anything is to acknowledge that you are capable of understanding it. True understanding will come with time and practice.

Course Authors

• Writing swirl Courses: An interactive guides and example for swirl course authors. The first group of lessons cover basics. The rest cover special topics useful primarily as samples--points of departure for one's own material. For more comprehensive documentation about writing your own swirl courses see http://swirlstats.com/swirlify/.

Install and run a course automatically from swirl

This is the preferred method of installing courses. It automates the process by allowing you to do everything right from the R console.

1. Make sure you have a recent version version of swirl:

install.packages("swirl")

2. Enter the following from the R console, substituting the name of the course that you wish to install:

library(swirl)
install_course("Course Name Here")
swirl()

For example, install_course("R Programming") will install the R Programming course. Please note that course names are case sensitive!

If that doesn't work for you...

Install and run a course manually

If the automatic course installation method outlined above does not work for you, then there's a simple alternative.

1. Find the course you want to install on the Swirl Course network website.
2. Follow the manual installation instructions on the course page.

If that does not work for you, consider taking a look at the legacy manual install instructions.

Uninstall a course

If you'd like to remove a course at any time, you can use uninstall_course("Course Name Here").

Using swirl in the classroom

Instructors around the world are using swirl in their classrooms. We think this is awesome. If you're an instructor, please feel free to do the same -- free of charge. While your students may be paying to take your course or attend your institution, we simply ask that you don't charge people directly for the use of our software or instructional content.

If you are not sure about a particular use case, don't hesitate to post a question to our Google Group.

swirl_courses's Issues

Problem with course... option 1 - in overview of statistics creates an error...

| Please choose a course, or type 0 to exit swirl.

1: Overview of Statistics
2: R Programming
3: Take me to the swirl course repository!

Selection: 1

| Please choose a lesson, or type 0 to return to course menu.

1: dependson.txt

[...]

Selection: 1

Error in file(con, "r") : invalid 'description' argument

| Leaving swirl now. Type swirl() to resume.

lesson list

Hi Swirl developers,
I just finished the Data Analysis / Data Visualization lesson and it says there is a "next lesson" to continue learning. However, it's unclear what lesson this is referring to! Does it exist?

Arthur

Bug with rm() in lesson

I keep getting an error when using rm() in a lesson. A small reproducible example follows. Create a lesson yaml that looks like:

• Class: meta
  Course: Bug
  Lesson: Bug
  Author: David Kane
  Type: Standard
  Organization: Williams College
  Version: 0.1.1
• Class: cmd_question
  Output: Assign 9 to x using x <- 9.
  CorrectAnswer: x <- 9
  AnswerTests: omnitest(correctExpr='x <- 9')
  Hint: Type x <- 9 to assign 9 to x.
• Class: cmd_question
  Output: Remove x from the workspace.
  CorrectAnswer: rm("x"")
  AnswerTests: any_of_exprs('rm("x")', 'rm(x)')
  Hint: Type rm("x") to remove x from the workspace.

Using testit(), I get:

set_lesson("~/Desktop/projects/swirl_courses/Bug/Bug/lesson.yaml")

This lesson is located at C:\Users\dkane\Desktop\projects\swirl_courses\Bug\Bug\lesson.yaml

If the lesson file doesn't open automatically, you can open it now to begin editing...

testit()

| Course installed successfully!

| | 0%

| Assign 9 to x using x <- 9.

x <- 9

| Perseverance, that's the answer.

|===================================================================================| 100%

| Remove x from the workspace.

rm(x)

| Perseverance, that's the answer.
Error in get(nm, globalenv()) : object 'x' not found

| Leaving swirl now. Type swirl() to resume.

Any ideas? I thought that this was working two weeks ago when I initially sent in a pull request with a new lesson for R Programming. But it does not seem to work now.

Character Font

The character font should be larger. I had difficultly, sometimes, in reading the material. Also I think it would present better (easier to read and absorb) if you forced your sentences to be no longer that 40 characters in length. But the larger font is the main issue I had in reading your material.

Alternative correct answer in Basic Building Blocks lesson

I was just working through the lesson and came across this question:

Output: To see another example of how this vector 'recycling' works, try adding
c(1, 2, 3, 4) and c(0, 10). Don't worry about saving the result in a new variable.

Wanting to save keystrokes on a whim, I typed c(1:4) + c(0, 10). Even though the result of this is equivalent to simply copying from the question directly, the course did not recognize it as correct.

Is there any reason for this to be so, such as it being impossible to have more than one answer to a question in swirl? If that is the case, would it not make more sense to store the intended output as the answer to the question when the output is what the question regards?

I apologize for my unfamiliarity with YAML, but could storing the result as correct be achieved by using the AnswerTests field, somehow?

Allow user to use single quotes in place of backticks

It seems backticks have been an issue for some people using non-English keyboards. We should allow students to use single quotes in addition to backticks, since their functionality seems to be identical in all standard use cases. Official docs at ?Quotes or ?backtick.

In particular, we ask the user to look up help for the colon operator beginning around line 51 of Sequences of Numbers in the R Programming course. In addition to the answer currently accepted, we should accept ?':'. I think we did something similar (accepting multiple answers) in another lesson recently.

@WilCrofter If you wouldn't mind adding the custom test (in a pull request), I can update the question wording (in that same pull request) to accommodate both responses.

dplyr no longer prints all rows if there are fewer than 100, now the threshold is 20

In the second swirl class of Getting_and_Cleaning_Data (Grouping_and_Chaining_with_dplyr) at the 47% mark, you are told to enter top_counts and you then see the comment:

| Hey, that's the first time we've seen more than the first 10 rows of our data! By default, if the
| dataset you're working with has more than 100 rows, dplyr will only print the first 10. Otherwise, it
| will print all rows, since it's not as overwhelming.

As of a commit to dplyr from October 2014, that is no longer true:

• Complaint: https://groups.google.com/forum/#!topic/manipulatr/zG0p0eZH5z8
• Ticket: tidyverse/dplyr#710
• Commit: tidyverse/dplyr@b006f82

The threshold is now 20, not 100. This changes the text of this answer as well as the next text:

| In this case, there are 61 packages in our top 1%, so dplyr has printed all of them. If we only want
| to see the first 20, we can use the head function like so: head(top_counts, 20).

and finally, this also impacts the text at 55%:

| ...And if you keep on going, you'll see swirl at number 43, with 820 total downloads. Sweet!

as you no longer see the 43rd entry in the output. The same is true for the output at 68%:

| Now Rcpp is in the lead, followed by stringr, digest, plyr, and ggplot2. swirl moved up a few spaces
| to number 40, with 698 unique downloads. Nice!

It may impact some of the thresholds chosen in the R code, such as countries > 60, in following examples, where you now only see the top 10 of the 46 results, if the intention was that you would see all results in this output.

Again, the text at 87% refers to an entry that is no longer visible:

| It looks like Rcpp is on top with downloads from 84 different countries, followed by digest, stringr,
| plyr, and ggplot2. swirl jumped up the rankings again, this time to 27th.

lesson5 (subset the 3rd, 5th, 7th element of x)

Please notice that I did it differently and supposedly correctly, yet the prompt 'made it sound' that I did it incorrectly = please see below

Various small quirks in Regression Models

Multivar examples 3: (note new Omnitest will fix this one)

summary(lm(Fertility ~ Agriculture, data = swiss))
# vs
summary(lm(Fertility ~ Agriculture, swiss))

Multivar examples 2:

summary(fit)$coefficient[,1]
# vs
summary(fit)$coef[,1]

Multivar examples 3:

colnames(hunger)
# is not considered correct while 
names(hunger)

Equals versus left arrow

Perhaps you are trying to enforce a good habit,
But I am consistently caught using "=" in my answers,
Instead of "<-",
Although I believe they are functionally equivalent.

I am taking R programming course from Coursera

I selected regression in starting and now I am unable to go to R programming. main() takes me to main page but it only give Regression or taking to SWIRL website option.

Want to complete my R assignment.

Best,
Jain

R Programming -The basics of programming in R - Not available

Hey all,

I'm still new to this whole world so first thanks for all the work getting this created! I love the concept and am excited to get started. I'll try and manually install this course, but i wanted to make sure someone was aware that it's not available via Swirl's automated installation. Below is the message i got after following the prompts.

| To begin, you must install a course. I can install a course for you from the internet, or I can send >you to a web page
| (https://github.com/swirldev/swirl_courses) which will provide course options and directions for >installing courses
| yourself. (If you are not connected to the internet, type 0 to exit.)

1: R Programming: The basics of programming in R
2: Regression Models: The basics of regression modeling in R
3: Don't install anything for me. I'll do it myself.

Selection: 1

| Sorry, but I'm unable to fetch <U+0091>R Programming: The basics of programming in >R<U+0092> right now. Are you sure you have an
| internet connection? If so, would you like to try again or visit the course repository for instructions on >how to install
| a course manually? Type 0 to exit.>

Suspected Bug….Swirl - Mathematical Bootcamp - two sample t test

In the 'Mathematical Biostatistics Boot Camp Two Sample t-test'

I get the following errors after inputting skip() at the following question:

Use the 'pt' function to compute the probability of getting a t-statistic that's greater than the value of the one we got and store this quanitity to a new variable called 'pVal1'. If you can't figure this one out on your own, then the hint will help you.

skip()
Error in pt(tStat, df = myDF, lower.tail = FALSE) :
unused argument (lower.tail = FALSE)
Leaving swirl now. Type swirl() to resume.

Originally my answer was

pVal1 <- pt(tStat, df = myDF, lower.tail=FALSE)

and i got the following error

Error in pt(tStat, df = myDF, lower.tail = FALSE) :
unused argument (lower.tail = FALSE)

Am i doing something wrong here? It is possible that my answer is just wrong - however that does not explain the error i get when i try to

skip()

Any advice or comments would be great! Thanks

Error? in lapply and sapply

Going through R Programming to test robust omnitest, I noticed that lapply rather should probably replace sapply in the answer below. The next question uses sapply and the point is to show that sapply reverts to lapply when it can't simplify.

- Class: cmd_question
  Output: "Since unique_vals is a list, you can use what you've learned to determine the length of each element of unique_vals (i.e. the number of unique values for each variable). Simplify the result, if possible. Hint: Apply the length() function to each element of unique_vals."
  CorrectAnswer: sapply(unique_vals, length)
  AnswerTests: omnitest(correctExpr='sapply(unique_vals, length)')
  Hint: Apply the length() function to each element of the unique_vals list using sapply(). Remember, no parentheses after the name of the function you are applying (i.e. length).

Quiz returning true whenever the result is integer(0)

In the Data Analysis course, In the central tendancy section there is a question to calculate mode from the data, when i write "order(table(myMPG),decreasing=T)[0]" which returns "integer(0)" it results in correct answer. This is applicable for every other question.

Error with answering Data Analysis: Central Tendency course item 17

Within the Data Analysis: Central Tendency course, when prompted to enter cars into the R command prompt, swirl seems to disregard this as a correct answer -- even skip() results in an error message.

| You are quite good my friend!

  |==========================                           |  48%

| Which of the following terms are of most importance when
| describing the central tendency of a data set?

1: mode, median, mean
2: statistics, population, mode
3: median, mode, range
4: population, sample, representative

Selection: 1

| You're the best!

  |===========================                          |  52%

| To illustrate these concepts, we will now look at a real
| dataset from the 'openintro' R package, which has already
| been loaded for you. Type 'cars' and press Enter to see the
| dataset we'll be working with.

> 
> cars
      type price mpgCity driveTrain passengers weight
1    small  15.9      25      front          5   2705
2  midsize  33.9      18      front          5   3560
3  midsize  37.7      19      front          6   3405
4  midsize  30.0      22       rear          4   3640
5  midsize  15.7      22      front          6   2880
6    large  20.8      19      front          6   3470
7    large  23.7      16       rear          6   4105
8  midsize  26.3      19      front          5   3495
9    large  34.7      16      front          6   3620
10 midsize  40.1      16      front          5   3935
11 midsize  15.9      21      front          6   3195
12   large  18.8      17       rear          6   3910
13   large  18.4      20      front          6   3515
14   large  29.5      20      front          6   3570
15   small   9.2      29      front          5   2270
16   small  11.3      23      front          5   2670
17 midsize  15.6      21      front          6   3080
18   small  12.2      29      front          5   2295
19   large  19.3      20      front          6   3490
20   small   7.4      31      front          4   1845
21   small  10.1      23      front          5   2530
22 midsize  20.2      21      front          5   3325
23   large  20.9      18       rear          6   3950
24   small   8.4      46      front          4   1695
25   small  12.1      42      front          4   2350
26   small   8.0      29      front          5   2345
27   small  10.0      22      front          5   2620
28 midsize  13.9      20      front          5   2885
29 midsize  47.9      17       rear          5   4000
30 midsize  28.0      18      front          5   3510
31 midsize  35.2      18       rear          4   3515
32 midsize  34.3      17      front          6   3695
33   large  36.1      18       rear          6   4055
34   small   8.3      29      front          4   2325
35   small  11.6      28      front          5   2440
36 midsize  61.9      19       rear          5   3525
37 midsize  14.9      19       rear          5   3610
38   small  10.3      29      front          5   2295
39 midsize  26.1      18      front          5   3730
40   small  11.8      29      front          5   2545
41 midsize  21.5      21      front          5   3200
42 midsize  16.3      23      front          5   2890
43   large  20.7      19      front          6   3470
44   small   9.0      31      front          4   2350
45 midsize  18.5      19      front          5   3450
46   large  24.4      19      front          6   3495
47   small  11.1      28      front          5   2495
48   small   8.4      33        4WD          4   2045
49   small  10.9      25        4WD          5   2490
50   small   8.6      39      front          4   1965
51   small   9.8      32      front          5   2055
52 midsize  18.2      22      front          5   3030
53   small   9.1      25      front          4   2240
54 midsize  26.7      20      front          5   3245

| Not quite right, but keep trying. Or, type info() for more
| options.

| Type 'cars' and press Enter. Do not use quotes, spaces, or
| uppercase letters.

> cars
      type price mpgCity driveTrain passengers weight
1    small  15.9      25      front          5   2705
2  midsize  33.9      18      front          5   3560
3  midsize  37.7      19      front          6   3405
4  midsize  30.0      22       rear          4   3640
5  midsize  15.7      22      front          6   2880
6    large  20.8      19      front          6   3470
7    large  23.7      16       rear          6   4105
8  midsize  26.3      19      front          5   3495
9    large  34.7      16      front          6   3620
10 midsize  40.1      16      front          5   3935
11 midsize  15.9      21      front          6   3195
12   large  18.8      17       rear          6   3910
13   large  18.4      20      front          6   3515
14   large  29.5      20      front          6   3570
15   small   9.2      29      front          5   2270
16   small  11.3      23      front          5   2670
17 midsize  15.6      21      front          6   3080
18   small  12.2      29      front          5   2295
19   large  19.3      20      front          6   3490
20   small   7.4      31      front          4   1845
21   small  10.1      23      front          5   2530
22 midsize  20.2      21      front          5   3325
23   large  20.9      18       rear          6   3950
24   small   8.4      46      front          4   1695
25   small  12.1      42      front          4   2350
26   small   8.0      29      front          5   2345
27   small  10.0      22      front          5   2620
28 midsize  13.9      20      front          5   2885
29 midsize  47.9      17       rear          5   4000
30 midsize  28.0      18      front          5   3510
31 midsize  35.2      18       rear          4   3515
32 midsize  34.3      17      front          6   3695
33   large  36.1      18       rear          6   4055
34   small   8.3      29      front          4   2325
35   small  11.6      28      front          5   2440
36 midsize  61.9      19       rear          5   3525
37 midsize  14.9      19       rear          5   3610
38   small  10.3      29      front          5   2295
39 midsize  26.1      18      front          5   3730
40   small  11.8      29      front          5   2545
41 midsize  21.5      21      front          5   3200
42 midsize  16.3      23      front          5   2890
43   large  20.7      19      front          6   3470
44   small   9.0      31      front          4   2350
45 midsize  18.5      19      front          5   3450
46   large  24.4      19      front          6   3495
47   small  11.1      28      front          5   2495
48   small   8.4      33        4WD          4   2045
49   small  10.9      25        4WD          5   2490
50   small   8.6      39      front          4   1965
51   small   9.8      32      front          5   2055
52 midsize  18.2      22      front          5   3030
53   small   9.1      25      front          4   2240
54 midsize  26.7      20      front          5   3245

| Give it another try. Or, type info() for more options.

| Type 'cars' and press Enter. Do not use quotes, spaces, or
| uppercase letters.

> skip()

| I've entered the correct answer for you.

| Give it another try. Or, type info() for more options.

| Type 'cars' and press Enter. Do not use quotes, spaces, or
| uppercase letters.

> 

Warning on exiting after selecting "2. Take me to the Swirl course repository"

(Nick, I'd not seen the issues section here. I'll use this to notify you from now on.)

NOTE: this may be solely be due to my locale being "English_United States.1252" rather than "en_US.UTF-8". However, my run through "Lesson 4: Dates and Times with lubridate" didn't throw off any warnings or errors until the second to last question, here:

| Now use as.period(how_long) to see how long it's been.

> as.period(how_long)
[1] "6y 3m 11d 21H 24M 55.1787569522858S"
Warning message:
In Ops.factor(left, right) : - not meaningful for factors

| Excellent job!

  |==========<snip>===========================================     |  96%

| This is where things get a little tricky. Because of things like leap years, leap seconds, ...

The next (last) question on stopwatch() didn't throw a warning or error.

However, the same warning appears on exiting Swirl, as shown here:

1: Getting and Cleaning Data
2: Take me to the swirl course repository!

Selection: 2

| OK. I'm opening the swirl courses web page in your browser.

| Leaving swirl now. Type swirl() to resume.

warning messages from top-level task callback 'mini'
Warning message:
In Ops.factor(left, right) : - not meaningful for factors

I recognize this may be a very minor matter but, as its appearence may drive a few dozen (hundred?) extra questions over the next few years, it may be worth your looking into it.

Thanks, as always, for a great tool.

lesson10 (command to produce 100 flips of an unfair coin and assign the result)

Looks like we can do it both ways, but the message says that I am not quite right - please see the attached.

Please note at the screen shot above that I originally assigned the result to flip, but then created a flip2 variable to compare the results.

Adding content

Should course authors add content to swirl_courses through a pull request, or through some other method?

Error in lm(jitter(child, 4) ~ parent, galton) : unused argument (galton)

Hi, in the introduction, at 30% when will be displayed the regression line I got this message:

Error in lm(jitter(child, 4) ~ parent, galton) : unused argument (galton)
| Leaving swirl now. Type swirl() to resume.

Thank you for your time.

Petronio

PS - I´m using RStudio 0.98.507 | Windows 7

?manip no longer exists in dplyr version 0.3

This is introduced in Manipulating_Data_with_dplyr lesson but the help page no longer exists
Ref: http://stackoverflow.com/questions/26487908/manip-no-longer-works-in-the-dplyr-0-3

Should understand that "=" is the same as "<-"

I'm just a beginner, but I'm also lazy, which means I don't like repeatedly typing unnecessary characters. I'm also possibly OCD-afflicted, but the fact that the "-" doesn't bisect the "<" in my font bothers me. Anyway, I prefer to type "=" instead of "<-", but while this (as far as I know) is treated by R as equivalent, in swirl I get "You almost got it" and similar encouragement to do better. I'd prefer it if swirl treated me like the unsung genius that I am, instead of like a bumbler.

typo in "R Programming > Simulation"

course name: R Programming
lesson name: Simulation
text containing the typo: Equivilently

This occurs at about 56%

(Minor) suggestions for Regression Course

• Mention how to load Galton dataset again for further experimentation?
• Fix plot scale so 45 deg angle of red line in first plot stands out?
• 'The regression line fits the data best in the sense of ordinary least squares.' -> 'This method of choosing the 'best' regression line (or 'fitting' a line to the data) is known as ordinary least squares.'
• Possible to provide links to the lectures or slides referred to in this course?

In R Programming, the display started showing percentage complete as I went along.

This happened when I started a lesson with "play()." When I typed "nxt()" to start the lesson proper, there was a "deprecated" message; thereafter,percentage complete showed up at each stage.

Error in file(con, "r") : invalid 'description' argument when running courses: MacOsx 10.9.5, R Studio Version 0.98.1049, R version 3.1.1

Hi There,

I am running Version 0.98.1049 and cannot run any coursed installed from swirl. I am getting the following error.

Please choose a course, or type 0 to exit swirl.

1: R Programming
2: swirldev-swirl courses-0abced2
3: Vectors
4: Take me to the swirl course repository!

Selection: 3

| Please choose a lesson, or type 0 to return to course menu.

1: customTests.R
2: lesson.yaml

Selection: 2

Error in file(con, "r") : invalid 'description' argument

| Leaving swirl now. Type swirl() to resume.

I have tried installing and re-installing, still get the same issue.
I am using R version 3.1.1

Regards
Tez

skip() and nxt() not working for certain flavor of inputs

I have been using the CLI (through ssh) to work through the various courses in swirl and as such do not get to see any of the boxplots. In this instance I would like to skip certain questions that pertain to the features of those graphs - I cannot find a way to do this. Neither the skip() or nxt() functions will escape when there is a "ANSWER:" prompt. Universal support of these functions would be valuable for people who use this configuration.

List of potential courses?

Hi, is there a list of potential swirl courses in this directory? I can't find one, only the instructions on how to install a course and a list of the "popular" courses. How can I see which courses are available?

Thanks!
Kate

Course Getting_and_Cleaning_Data / Lubridate / user Loop on error check with skip

In some circumstances, user continues in a loop unable to progress.

Add basic description of all courses

Requested in issue #36

typo in swirl_courses/R_programming/Vectors/lesson.yaml

At row 145, ' it''s ' should be ' its '.

Thanks,
Margherita

Help with functions?

It would be great to have a course on functions. I've attempted the R Programming course on Coursera twice, but I just have trouble making the leap from the videos to the first assignment. It would be excellent to have optional assignments or a swirl module to work through these much more in depth.

Lubridate examples in Getting and Cleaning Data course assume English locale

If user's locale not English (?US), examples don't work as expected. Need to warn I guess. I raised an issue on lubridate too which I noticed as a result: [https://github.com/tidyverse/lubridate/issues/255]

Connect the slides to the Swirls

Hi!
I'll be writing my Bachelor thesis in statistics this fall and I use the Coursera course (regression models) and this swirl to get back on track with R-programing. The Swirl idea is awesome! One thing, though, that would make it even better would be if in every task in the Swirl a number would be displayed to the corresponding slide from Coursera.
Thanks for a great interactive learning platform!
Filip

Unable to Install all the courses in Mac by downloading Zip file

Hi,

I am using Mac OS and R Studio, but whenever i try to install this courses manually from the zip file I am getting the following error:

Error in unzip(path, list = TRUE) :
zip file '/Users/Dibs/Downloads/swirl_courses-master.zip' cannot be opened

Request any suggestion

Request for feedback on new lessons

I've added 5 new lessons to R programming and a new course called Getting and Cleaning Data (4 lessons so far). I'd love to hear what everyone thinks if you have some time to work through them.

I'm very open to feedback, as I've tried some new approaches, particularly with the script-based questions in Getting and Cleaning Data.

Allow parantheses around logical expressions in R Programming, section 8

!(5==7) is not recognized as a correct answer while !5==7 is. Please allow for parantheses as well.

  |==========================                                                                     |  27%
| In order to negate boolean expressions you can use the NOT operator. An exclamation point `!` will
| cause !TRUE (say: not true) to evaluate to FALSE and !FALSE (say: not false) to evaluate to TRUE. Try
| using the NOT operator and the equals operator to find the opposite of whether 5 is equal to 7.

> !(5==7)
[1] TRUE

| That's not exactly what I'm looking for. Try again. Or, type info() for more options.

| This expression may be a little tricky, so think about negating the expression 5 == 7 (all you need is
| an exclamation point in front).

> !5==7
[1] TRUE

| That's the answer I was looking for.

rm("mydf") glitch

See this thread in the Swirl Discussion group.

NOTE: I've been unable to reproduce the problem.

Account for International users that don't have their locale set to English

for those that have access to coursera MOOC ... , here's the issue to solve ... I'll post a fix in a second if this is acceptable to you. https://class.coursera.org/getdata-016/forum/thread?thread_id=275#post-1116

in ### Manipulating data with dplyr - Getting and Cleaning Data ### use of summarise should be as good as summarize

Hi, thanks for an excelent way to learn R.
in the Getting and Cleaning Data course, near the end of Manipulating Data with dplyr,
I was introduced to summarize(). Being used to using UK spelling, i used summarise() which gave the correct output, but swirl did not acnowleage this and asked me to try again.

Data Analysis Central Tendency Error

R automatically quits on Data Analysis, Central Tendency Lesson. Margins need to be fixed.

Message:

| Here is a diagram showing the relationship between a population and a sample.

Error in plot.new() : figure margins too large

include progress indicator for course install / takes very long, appears to hang

Whenever I select something from the below, R appears to hang, I get a blank like with a cursor (no prompt), and RStudio tells me that the R Session is busy.

There is no progress indicator.

This might easily be misunderstood as a hang (I did). The process appears to take minutes on a 6Mbit down line.

I got: OS X 10.10, R 3.1.2, RStudio 0.98.1079.

| To begin, you must install a course. I can install a course for you from the internet, or I can send you to a web page
| (https://github.com/swirldev/swirl_courses) which will provide course options and directions for installing courses
| yourself. (If you are not connected to the internet, type 0 to exit.)

1: R Programming: The basics of programming in R
2: Regression Models: The basics of regression modeling in R
3: Don't install anything for me. I'll do it myself.

Selection: 1

this is the part that takes forever, with no indication of progress

| Course installed successfully!


| Please choose a course, or type 0 to exit swirl.

1: R Programming
2: Take me to the swirl course repository!

Yipeeh!

Also, fantastic work.

Open Intro problem

In the Open Intro course, no stem-and-leaf-plot is displayed for me (around 57% of first lecture (if there are more than one)).

I'm using R 3.1.0 x64 in RStudio 0.98.507 under Win 8.1 and installed the Open Intro package yesterday.

Typo in R Programming vapply/tapply module

Typo in the vapply/tapply lesson. Should be 'countries' not 'counties'

I 88%
I what is the median population (in millions) for counties
I without the color red on their flag?

Statistical_Inference/Resampling hanging near end of lesson

Thank you for an excellent collection of lessons. I am new to R (and GitHub) and having been working through all the Swirl lessons. Very enjoyable and informative. The only insurmountable issue I have encountered was near the end of the last lesson

The Statistical_Inference / Resampling lesson keeps repeating
"Nice try, but that's not exactly what I was hoping for. Try again. Or, type info() for more options."
"Type perms <- sapply(1 : 10000, function(i) testStat(BCcounts, sample(group))) at the command prompt."

This happens no matter how I try to type the command (even if I cut/paste) the prompt text.

I found the offending point at line 303-307 on https://github.com/swirldev/swirl_courses/blob/master/Statistical_Inference/Resampling/lesson
which looks correct but still repeats in RStudio.

I look forward to additional courses.

dplyr version: there is no 2.0

"""If your dplyr version is not at least 2.0, then you should hit the Esc key
| now, reinstall dplyr, then resume this lesson where you left"""

There's only a version 0.2 of dplyr, not 2.0
http://cran.r-project.org/web/packages/dplyr/index.html

Misspelling in Getting and Cleaning Data part 2/4 Grouping and Chaining with dplyr

The word equivalent is misspelled.

"That's exactly what we've done in this script. The result is equivilent, but the code is much less readable and some of the arguments are far away from the function to which they belong. Again, just try to understand what is going on | here, then submit() when you are ready to see a better solution."

package dependencies for regression lessons

@WilCrofter -- I know we've got a dependson.txt for the first Regression lesson:

https://github.com/swirldev/swirl_courses/blob/master/Regression_Models/Introduction/dependson.txt

Would you mind adding one for each of the later lessons that has package dependencies? I expect that your Regression course will be getting more and more attention, and people will get namespace errors if they don't have the required packages installed.

Also, please feel free to add it to the "Popular Courses" list on the readme if you feel pretty good about what's there. I'm very excited about it.

Important notation question

Does everyone find my convention of using backticks (``) to denote R expressions in swirl content to be helpful or distracting and/or confusing? It's trivial for me to remove them from the R Programming course if you think I should. Please let me know ASAP.

P.S. -- I've added 3 lessons to R Programming in the last couple of days and I'd greatly appreciate any feedback before they go live on Coursera.

Regression Models link typo

Lesson 2 'Residuals' of the Regression Models swirl course reads:
This lesson corresponds to Regression_Models/01_02_linearRegression.,
refering to https://github.com/DataScienceSpecialization/courses/tree/master/07_RegressionModels/01_02_linearRegression,
which is a page that doesn't exist.

Possibly it should be 01_02_notation or another section.

The lesson also refers to equations "in the slides" for the intercept and slope which are difficult to identify; they don't seem to be in 01_02_notation.