100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary Introduction to R programming in Biology $3.23   Add to cart

Summary

Summary Introduction to R programming in Biology

 5 views  0 purchase
  • Course
  • Institution

This exam sheet contains all the codes needed for the exam Introduction to R programming in Biology. This sheet will help you to receive a high exam grade. Good luck!

Preview 1 out of 3  pages

  • November 13, 2024
  • 3
  • 2020/2021
  • Summary
avatar-seller
LU1: vectors, matrix()
- my_first_matrix <- matrix(c(1, 3, 5, 7, 9, 11), nrow = 2, ncol = 3, byrow = TRUE)
- round(sqrt(42), digits = 1)

LU2: class(), is.logical(), as.numeric(), data.frame(), array(), list()

Checking data type: class(my_object) Converting data type: my_numeric_object <- as.numeric(my_object)
- datfr <- data.frame(x = c(1:3), y = c(“A”, “B”, “C”))
- arr <- array(c(height1, height2, weight1, weight2), dim = c(5, 2, 2))
- somelist <- list(vector = shortv, matrix = shortm, factor = shortf)

LU3: rm(), save(), load(), getwd(), setwd(), rownames(), duplicated(), unique(), any(is.na()), complete.cases(), rbind(),
merge(

Removing objects from workspace or whole workspace: rm(second_object) rm(list = ls())

Check working directory: getwd() Set working directory: setwd(“U:/my_WD”)
- Save objects: save(first_object, second_object, third_object, file = “multiple_objects.RData”)
- Write csv after creating df: write.csv(test_data, file = “Derived_data/test_data.csv”, row.names = FALSE)
- Read csv in R: COVID_data <- read.csv(“Raw_data/COVID-19_casus.csv”, header = TRUE, sep = “,”,
stringsAsFactors = FALSE)

Change rownames: rownames(iris) <- paste(“flower”, rownames(iris), sep = “_”)
Rename all columns: colnames(iris) <- c(“Sepal Length [cm]”, “Petal Length [cm]”)

- Check for duplicates in data set: duplicated(iris)  Remove duplicates from data: unique_iris <- unique(iris)
- Check for missing values (NA): any(is.na(iris))  Remove NA: complete_iris <- iris[complete.cases(iris), ]

LU4: subset(), which(), seq(), rep(), sort(), order(), if else statements

Select columns/rows: select row 1 and 3 from column 5  esoph[c(“1”, “3”), “ncontrols”]

Subset: subset(data set, condition(s), select (optional)):
Subset esoph highest tobgp AND equal to 0 cases  esoph[esoph$tobqp == “30+” & esoph$ncases == 0, ]
subset(esoph, ncases == 17, select = c(agegp, ncases))

Get rid of NA values while subsetting  newDat[which(newDat$y > 6, ]

Omitting data: omit row 20 – 88  esoph[-c(20:88), ]
- subset(esoph, ncases == 17, select = -ncontrols)
- Retain function: ncases less than 1 are retained  subset(esoph, !ncases >= 1)

Sequences: subset esoph so only first four rows and 1, 3, 5 column  esoph[seq(from = 1, to = 4, by = 1), seq(from = 1, to =
5, by = 2)]

Sorting/ordering data sets from low to high:
- Increasing: sort(esoph$tobgp) Decreasing  sort(esoph$ncases, decreasing = TRUE)
- Ranking vectors/data frames  esoph[order(esoph$ncases, decreasing = TRUE), ]

if (esoph$ncontrols[6] > esoph$ncontrols[38]){
print ("Observation 6 has more controls than 38")
} else if (esoph$ncontrols[6] < esoph$ncontrols[38]){
print ("Observation 6 has fewer controls than 38")
} else{
print ("Observation 6 has the same number of controls than 38")
}


LU5: summary(), min(), max(), mean(), median(), quantile(), colMeans(), rowMeans(), colSums(), rowSums(), table(),
aggregate(), hist(), plot(density()), qqnorm()  qqline(), boxplot(), length()

Before doing summary statistics (summary())  unique() and any(is.na()) to see if there are still NA or missing values
- quantile(InsectSprays$count, probs = c(0.25, 0.75))

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller qlmedical. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $3.23. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

73918 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$3.23
  • (0)
  Add to cart