r programming assignment 3 quiz

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R Programming Project 3

github repo for rest of specialization: Data Science Coursera

The zip file containing the data can be downloaded here: Assignment 3 Data

Part 1 Plot the 30-day mortality rates for heart attack ( outcome.R )

Part 2 Finding the best hospital in a state ( best.R )

Part 3 ranking hospitals by outcome in a state ( rankhospital.r ), part 4 ranking hospitals in all states ( rankall.r ).

vickkiee commented Jul 7, 2020

Thank you for your solution

Sorry, something went wrong.

ghost commented Jul 15, 2020 • edited by ghost

The course isn't for the student's learning ability but for student's cheating ability. This course didn't teach me or explain me to find the solution to solve the assignment; in contrast, it encouraged me to google and copy other's code. I am feeling that I am in the wrong course. I am about to quit. I have no idea why JHU and instructor created irresponsible course like this.

sushilsushil commented Jul 18, 2020

Yo everyone feels the same way. I didn't like the constant saliva sound of that guy. Very poor course design too.

BouNaj commented Jul 25, 2020

I share the same feeling. I was frustrated the content does in no way prepare you to do anything of the sort the assignments require.

Chiagozie-Umeano commented Aug 4, 2020

I thought I was the only one having this difficulty in writing code and functions. Was feeling bad for choosing this course, we are not properly taught how to write these codes. I have being feeling to quit the course..

abduljan71 commented Aug 7, 2020

Hey, I am with it. I am doing the same. The course itself does not help you that much for you to understand and do your own coding. I feel very bad.

shaunkok64 commented Aug 16, 2020 • edited

Thank you for your solution. I am glad that there are so many people feeling the same. As I don't have any knowledge regarding coding in general and I wanted to take this course to learn something new such as Data Science. This course could be great if designed properly but the course is not that learner friendly, in some cases even people with experience with coding may not able to cope it and this has led me thoughts to quit. This course are expecting learners to do their own coding without giving guidance to learners. WHY! There are so little guidance given to readers until I had to Google Search for answers. I need to take sometime to study it after I have passed this.

Gareeeb7 commented Aug 27, 2020

Utha re ba ba uthle Coursera ko

Thanks for your Solution

Fahad-98 commented Aug 30, 2020

How do I submit my assignment.

SaneClouxz commented Sep 14, 2020

How do I submit my assignment. It's a multi choice quiz which you'll solve using the functions provided in this solution.

nfabregas commented Sep 25, 2020

Same here. The problem is simple: the course don't give you the tools and knowledge that someone with no experience with code needs to do the Assignments. It looks like assignments are from another course.

100% agree with D-Se:

Coursera lecture: "The drivetrain of a car looks like this" Swirl: "A car can move hurr durrr" Assignment: "build a car and test it, or else fail the course"

anikvh commented Sep 25, 2020

I agree with the comments above, there is a huge gap between the lectures and the assingments. Thank you so much for sharing this!

Songsuperjing commented Sep 27, 2020

love the above comments. so true.

Arnab-eco commented Oct 8, 2020 • edited

I totally agree with the comments. Unfortunately, The instructor thinks that everyone is a master level programmer. His presentations lack the necessary insight. His assignments are way over the mark. I understand that if someone can complete these assignments, they can learn a lot. But frankly, it's like asking someone to write a novel after teaching them how to read. The swirl exercises do teach the basics, but is absolutely hopeless as it doesn't even allow us to make the smallest changes to a code.

benthecoder commented Oct 18, 2020 • edited

I'm glad many are learning this specialization even today, I was hoping if anyone can direct me to any discord servers or like reddit groups to talk about the assignments, for discussions and to learn from each other. Thanks! And yea the assignments are crazy hard, but to be fair the coursera courses can't fit everything into their videos, so i believe it's encouraged to find ways to create a solution for yourself with the abundance of resources online.

is this part wrong? return(dt[order(state, get(outcome), hospital name ) , head(.SD, num) , by = state , .SDcols = c("hospital name")])

I can't seem to get the right answers with this part. Anyone has a revision of this part of the code?

siyangni commented Nov 26, 2020 • edited

This course is just designed to make me feel bad. I was in the honor's college while I was a senior, now I am getting my master in sociology. Throughout my academic career so far I've never Googled anyone else's assignment. And this course makes me do this for every assignment!!!!!! By the way, I have a decent knowledge of programming where I gain from learning Python. I thought this class would be easy for me (after quickly going through the lecture videos), yet from the first assignment I began to scratch my head for an answer.

Guess what? the following courses for this specialization are just no better. At first sight I thought the instructors may have problems with their pedagogy. After going through several courses of JHU's Data Science Specialization, I highly doubt it's not just pedagogy, it is their attitude. There is no way the three instructors who should be incredibly smart people cannot find the embarrassingly obvious large gap between the course material and the assignments/quizzes in every one of their courses. And they rush through every course in this specialization. I paid for those courses though! I really want to file a complaint on Coursera.

amingraphy commented Nov 28, 2020

I agree the course it useless. Instead I started learning by reading a time-consuming textbook, called "discovering statistics using R". I even think the material provided by Roger Peng are not all in the same basic level. He doesn't teach basic tools of R, but then he jumps to using multi-core computation on your computer to speed up the calculation! It is just ridiculous

DanEscasa commented Dec 30, 2020 • edited

Thanks for the hard work. I chose not to shorten the unwieldingly long column names, just used switch :

outcome <- switch(outcome, "heart attack" = "Hospital.30.Day.Death..Mortality..Rates.from.Heart.Attack", "heart failure" = "Hospital.30.Day.Death..Mortality..Rates.from.Heart.Failure", "pneumonia" = "Hospital.30.Day.Death..Mortality..Rates.from.Pneumonia", NULL) if (is.null(outcome)) { stop(" : invalid outcome") }

<rant> Isn't there a way to preserve the indentation in a code block? </rant>

As to Roger Peng's teaching, I was looking for a functional programming-oriented approach. He still treats it like a procedural language. I should write up something on that in codementor.io

charlenelch13 commented Jan 3, 2021

Thank you so much for the sharing!! It is sooo helpful! I had zero knowledge about programming before taking this course. I feel frustrated about learning the logics from the course materials. They are so vague and not supported by daily examples. I don't know how they can assume students to know how to finish the assignments... Thank you for guiding me!!

EmilieWaite18 commented Mar 23, 2021

I have never been so frustrated by anything. I have had to look up every single answer to these assignments.

anaidcandido commented Jun 1, 2021

Many thanks for sharing!! I also thought I was the only one struggling with the course but I'm "glad" to see is the course itself. Now I am able to analyze and compare what I was doing. Thanks a lot!

yeho-bt commented Jun 13, 2021

Hmmmm, I am not alone feeling like this.

jdpm93 commented Oct 5, 2021

I have the same problem, the gap between the lessons, swirl, and the assigments is horrible and frustrating. some excercises require the use of things never covered in the videos or swirl, I see that many have sent feedback but they are not taking action on this, also the video lessons need to be updated it's 2021 and the videos were recorded in 2015. this is insane. Thank you for sharing.

codobene commented Dec 16, 2021

truth is, the world is not meant for everyone to be kept alive - it just needs the upper 10% of people that manage this course well. Same is true for jobs in general, stock market, etc etc get it quickly, or work overtime to compensate for your idiocy, or become social darvinism's fish food.

i blindly copy code that I find here, fail to reproduce anything, and take drugs. good night. good luck!

Juanvelz commented Mar 24, 2022

These people should learn how to teach before offering a course. On the other hand, they know very well how to discourage students.

emakello commented Mar 27, 2022

The essence of taking an online course is to learn skills that can help you in your career or academics. While the courses are stimulating, it makes no sense to bring assignments that discourage rather than encourage learners. Some people like me had never coded before and I spend hours trying to do this thing without success. I wish there was someone who could teach coding from scratch without assuming any prior knowledge.

cfsobral commented Jan 22, 2023

Thank you for help. I believe that the course already expects us to look for solutions like this one from mGalarnyk, otherwise it would not make sense to pass on an assignment of this complexity for beginners to do, because many like me would get frustrated and give up the course, as I read in some comments made here. Thank you mGalarnyk

Doc-OmSa commented Apr 9, 2023

Thanks mGalarnyk. I have a feeling that this course is definitely not for beginners, unlikely for intermediates as well. The assignments are too advanced. I have been struggling to understand functions. I am a beginner having taken the Google Data Analutics course previously. This is too advanced. Would likely leave. Just wanted to ask if there are better courses more suitable for someone who is a beginner and going to intermediate level? An other platform?

 Quiz: R Fundamentals

Test your basic understanding of R language syntax and R programming by taking the quiz "R Fundamentals". This quiz consists of ten questions, each with three to five possible answers, at least one of them is correct. There may be multiple correct or incorrect answers. Check those answers that you think are correct, then click the "Submit Quiz" button. If you have answered at least 50% of the answers correctly, you are prepared to take R a step further, for example by learning about functions and data visualization with R and R Studio. Have fun!

The topics of this quiz are: using the RStudio environment, using the help, comments, variables and data types, assignments, and using basic data structures such as vectors, matrices and data frames. Check the R Tutorial on this site for a brief introduction to these topics, or the references below for in-depth explanations.

 Quiz: R Functions

Test your basic understanding of programming and using R functions by taking the quiz "R Functions". This quiz consists of ten questions, each with three to five possible answers, at least one of them is correct. There may be multiple correct or incorrect answers. Check those answers that you think are correct, then click the "Submit Quiz" button. If you have answered at least 50% of the answers correctly, you are prepared to take R a step further, for example by learning about data visualization, classification and regression models. Have fun!

The topics of this quiz are: user-defined functions, with and without return value, R built-in functions, binary operators, R packages. Check the R Tutorial on this site for a brief introduction to these topics, or the references below for in-depth explanations.

Tools & References

• R Tutorial "Fundamentals"
• The R project: r-project.org/
• The Comprehensive R Archive Network: cran.r-project.org/
• An introduction to R: cran.r-project.org/doc/manuals/r-release/R-intro.html
• Quick list of useful packages: support.rstudio.com/hc/en-us/articles/201057987-Quick-list-of-useful-R-packages
• Tidyverse: R packages for data science: https://www.tidyverse.org/
• R for Data Science: https://r4ds.had.co.nz/

R programming Assignment 3 week 4

Course 2 r programming, assignment 3 (week 4), under data science by johns hopkins university, 1 plot the 30-day mortality rates for heart attack, 3 ranking hospitals by outcome in a state, 4 ranking hospitals in all states.

R Programming Assignment 3: Hospital Quality

Introduction.

Download the file ProgAssignment3-data.zip file containing the data for Programming Assignment 3 from the Coursera web site. Unzip the file in a directory that will serve as your working directory. When you start up R make sure to change your working directory to the directory where you unzipped the data.

The data for this assignment come from the Hospital Compare web site ( http://hospitalcompare.hhs.gov ) run by the U.S. Department of Health and Human Services. The purpose of the web site is to provide data and information about the quality of care at over 4,000 Medicare-certified hospitals in the U.S. This dataset essentially covers all major U.S. hospitals. This dataset is used for a variety of purposes, including determining whether hospitals should be fined for not providing high quality care to patients (see http://goo.gl/jAXFX for some background on this particular topic).

The Hospital Compare web site contains a lot of data and we will only look at a small subset for this assignment. The zip file for this assignment contains three files:

• outcome-of-care-measures.csv : Contains information about 30-day mortality and readmission rates for heart attacks, heart failure, and pneumonia for over 4,000 hospitals.
• hospital-data.csv : Contains information about each hospital.
• Hospital_Revised_Flatfiles.pdf : Descriptions of the variables in each file (i.e the code book).

A description of the variables in each of the files is in the included PDF file named Hospital_Revised_Flatfiles.pdf . This document contains information about many other files that are not included with this programming assignment. You will want to focus on the variables for Number 19 (“Outcome of Care Measures.csv”) and Number 11 (“Hospital Data.csv”). You may find it useful to print out this document (at least the pages for Tables 19 and 11) to have next to you while you work on this assignment. In particular, the numbers of the variables for each table indicate column indices in each table (i.e. “Hospital Name” is column 2 in the outcome-of-care-measures.csv file).

Part 1: Plot the 30-day mortality rates for heart attack

Read the outcome data into R via the read.csv function and look at the first few rows.

There are many columns in this dataset. You can see how many by typing ncol(outcome) (you can see the number of rows with the nrow function). In addition, you can see the names of each column by typing names(outcome) (the names are also in the PDF document).

To make a simple histogram of the 30-day death rates from heart attack (column 11 in the outcome dataset), run

Because we originally read the data in as character (by specifying colClasses = “character” we need to coerce the column to be numeric. You may get a warning about NAs being introduced but that is okay.

There is nothing to submit for this part.

Part 2: Finding the best hospital in a state

Write a function called best that take two arguments: the 2-character abbreviated name of a state and an outcome name. The function reads the outcome-of-care-measures.csv file and returns a character vector with the name of the hospital that has the best (i.e. lowest) 30-day mortality for the specified outcome in that state. The hospital name is the name provided in the Hospital.Name variable. The outcomes can be one of “heart attack”, “heart failure”, or “pneumonia”. Hospitals that do not have data on a particular outcome should be excluded from the set of hospitals when deciding the rankings.

Handling ties. If there is a tie for the best hospital for a given outcome, then the hospital names should be sorted in alphabetical order and the first hospital in that set should be chosen (i.e. if hospitals “b”, “c”, and “f” are tied for best, then hospital “b” should be returned).

The function should use the following template.

The function should check the validity of its arguments. If an invalid state value is passed to best , the function should throw an error via the stop function with the exact message “invalid state”. If an invalid outcome value is passed to best , the function should throw an error via the stop function with the exact message “invalid outcome”.

Here is some sample output from the function.

Save your code for this function to a file named best.R .

Part 3: Ranking hospitals by outcome in a state

Write a function called rankhospital that takes three arguments: the 2-character abbreviated name of a state ( state ), an outcome ( outcome ), and the ranking of a hospital in that state for that outcome ( num ). The function reads the outcome-of-care-measures.csv file and returns a character vector with the name of the hospital that has the ranking specified by the num argument. For example, the call

would return a character vector containing the name of the hospital with the 5th lowest 30-day death rate for heart failure. The num argument can take values “best”, “worst”, or an integer indicating the ranking (smaller numbers are better). If the number given by num is larger than the number of hospitals in that state, then the function should return NA . Hospitals that do not have data on a particular outcome should be excluded from the set of hospitals when deciding the rankings.

Handling ties . It may occur that multiple hospitals have the same 30-day mortality rate for a given cause of death. In those cases ties should be broken by using the hospital name. For example, in Texas (“TX”), the hospitals with lowest 30-day mortality rate for heart failure are shown here.

Note that Cypress Fairbanks Medical Center and Detar Hospital Navarro both have the same 30-day rate (8.7). However, because Cypress comes before Detar alphabetically, Cypress is ranked number 3 in this scheme and Detar is ranked number 4. One can use the order function to sort multiple vectors in this manner (i.e. where one vector is used to break ties in another vector).

The function should check the validity of its arguments. If an invalid state value is passed to rankhospital , the function should throw an error via the stop function with the exact message “invalid state”. If an invalid outcome value is passed to rankhospital , the function should throw an error via the stop function with the exact message “invalid outcome”.

Save your code for this function to a file named rankhospital.R .

Part 4: Ranking hospitals in all states

Write a function called rankall that takes two arguments: an outcome name ( outcome ) and a hospital ranking ( num ). The function reads the outcome-of-care-measures.csv file and returns a 2-column data frame containing the hospital in each state that has the ranking specified in num . For example the function call rankall(“heart attack”, “best”) would return a data frame containing the names of the hospitals that are the best in their respective states for 30-day heart attack death rates. The function should return a value for every state (some may be NA ). The first column in the data frame is named hospital , which contains the hospital name, and the second column is named state , which contains the 2-character abbreviation for the state name. Hospitals that do not have data on a particular outcome should be excluded from the set of hospitals when deciding the rankings.

Handling ties . The rankall function should handle ties in the 30-day mortality rates in the same way that the rankhospital function handles ties.

NOTE : For the purpose of this part of the assignment (and for efficiency), your function should NOT call the rankhospital function from the previous section.

The function should check the validity of its arguments. If an invalid outcome value is passed to rankall , the function should throw an error via the stop function with the exact message “invalid outcome”. The num variable can take values “best”, “worst”, or an integer indicating the ranking (smaller numbers are better). If the number given by num is larger than the number of hospitals in that state, then the function should return NA .

Save your code for this function to a file named rankall.R .

My Solution

A good tutorial.

Link: https://github.com/DanieleP/PA3-tutorial

• 1. Introduction
• 2. Part 1: Plot the 30-day mortality rates for heart attack
• 3. Part 2: Finding the best hospital in a state
• 4. Part 3: Ranking hospitals by outcome in a state
• 5. Part 4: Ranking hospitals in all states
• 6. My Solution
• 8. A Good Tutorial

• [Programming Assignment 1] R Programming
• by Anderson Hitoshi Uyekita
• Last updated almost 2 years ago
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Week 4 Quiz >> R Programming

1. What is produced at the end of this snippet of R code?

• A vector with the numbers 1, 4, 1, 1, 5
• A vector with the numbers 1, 1, 2, 4, 1
• It is impossible to tell because the result is random
• A vector with the numbers 3.3, 2.5, 0.5, 1.1, 1.7

2. What R function can be used to generate standard Normal random variables?

3. When simulating data, why is using the set.seed() function important? Select all that apply.

• It can be used to specify which random number generating algorithm R should use, ensuring consistency and reproducibility.
• It can be used to generate non-uniform random numbers.
• It ensures that the sequence of random numbers is truly random.
• It ensures that the random numbers generated are within specified boundaries.

4. Which function can be used to evaluate the inverse cumulative distribution function for the Poisson distribution?

5. What does the following code do?

• Generate data from a Normal linear model
• Generate data from a Poisson generalized linear model
• Generate random exponentially distributed data
• Generate uniformly distributed random data

6. What R function can be used to generate Binomial random variables?

7. What aspect of the R runtime does the profiler keep track of when an R expression is evaluated?

• the package search list
• the function call stack
• the working directory
• the global environment

8. Consider the following R code

(Assume that y, x1, and x2 are present in the workspace.) Without running the code, what percentage of the run time is spent in the ‘lm’ function, based on the ‘by.total’ method of normalization shown in ‘summaryRprof()’?

• It is not possible to tell

9. When using ‘system.time()’, what is the user time?

• It is the “wall-clock” time it takes to evaluate an expression
• It is a measure of network latency
• It is the time spent by the CPU waiting for other tasks to finish
• It is the time spent by the CPU evaluating an expression

10. If a computer has more than one available processor and R is able to take advantage of that, then which of the following is true when using ‘system.time()’?

• user time is 0
• elapsed time may be smaller than user time
• user time is always smaller than elapsed time
• elapsed time is 0

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