--- title: "BIF20806_week1day1_notebook" editor: source date: ADD author: ADD registration_number: ADD format: html execute: eval: false --- # The importance of data analysis ## Set up your R environment ```{r setup} options(repos = c(CRAN = "https://cloud.r-project.org")) ### Some of you will have problems with setting the workdirectory (setwd()) ### Here you need to set your work directory as well #knitr::opts_knit$set(root.dir = "D:/") ``` ### Getting to grips with R (exercise) Start RStudio and browse through to find out: 1. Which version of R are you running? 2. Where can you find which packages are activated? 3. Which version of the stats package is active? 4. Where on your Harddrive is the current (default) working directory? ### Prepare your documentation (exercise) Open the Quarto markdown template in RStudio and fill in your own information. ### Set a work directory Here you can add notes to help yourself in the future. ```{r} ###this is a code-chunk, where you can write and execute R-code ###this function you can use to automatically set a location; you might not have a D-drive. #setwd("D:/") ###Note that you need to set it as well in the {r setup} chunk at the start of this document. ``` ### Install packages (excercise) Here you can add notes to help yourself in the future. ```{r} ### you find how to do this further in the book ``` ### Activate packages (excercise) Here you can add notes to help yourself in the future. ```{r} ### you find how to do this further in the book ``` ## Loading data into R Here you can add notes to help yourself in the future. ```{r} # Maybe you need to add the path to your tab-delimited file pheno_data <- read.delim("./BIF20806_Warmerdam_dataset.txt") ``` ## Inspecting data ### Using functions Here you can add notes to help yourself in the future. ```{r} ### inspection functions # Check the first 6 rows head(pheno_data) # Check the last 6 rows tail(pheno_data) # get a summary of the data (per column) summary(pheno_data) ## accessing data # The 18th row pheno_data[18,] # The 3rd column pheno_data[,3] # Or combined the 18th row of the 3rd column pheno_data[18,3] # the 18th value of the Line column; as a vector is one-dimensional only 1 coordinate is needed. pheno_data$Line[18] ``` ### Inspect and clean data using ggplot2 and tidyverse Here you can add notes to help yourself in the future. ```{r} ###Boxplot ggplot2::ggplot(pheno_data,aes(x=genotype,y=eggmass)) + geom_boxplot() ``` ### Histogram (exercise) Here you can add notes to help yourself in the future. ```{r} ``` ### Use table to inspect observation per genotype Here you can add notes to help yourself in the future. ```{r} ### this way you can figure out how the function works ?table() table(pheno_data$genotype) ``` ### Make a table (excercise) Here you can add notes to help yourself in the future. ```{r} ``` ## Cleaning and preparing the data Not done in this excercise. ## Analyzing ### Normal distribution Here you can add notes to help yourself in the future. ```{r} ### Using a plot ggplot(pheno_data,aes(sample=eggmass)) + stat_qq() + stat_qq_line() ### Using a statistical test shapiro.test(pheno_data$eggmass) ``` ### Does the data follow a normal distribution? (exercise) You now conducted two types of analyses that tell you whether the data is normally distributed. (1) what do you see in the qqplot, and what does it mean? (2) what is the p-value from the Shapiro-Wilk test? (3) what does a p-value mean? ### T-test Here you can add notes to help yourself in the future. ```{r} ### filter the data data.test <- dplyr::group_by(pheno_data,screening) %>% dplyr::filter(("Col-0" %in% Line & "Cvi-0" %in% Line)) %>% dplyr::ungroup() %>% dplyr::filter(Line %in% c("Col-0","Cvi-0")) ### Conduct the statistical test t.test(eggmass~Line,data=data.test) ###you should have p-value = 2.588e-06 ``` ### How to interpret a p-value? (exercise) You now have tested a null-hypothesis and found that the chance his data agrees with this null-hypothesis is very small. What is the *biological interpretation* of this p-value? ## Presenting ### Boxplot Here you can add notes to help yourself in the future. ```{r} ### Simple boxplot ggplot(data.test,aes(x=Line,y=eggmass)) + geom_boxplot() + geom_jitter(height=0,width=0.25) ### Fancier boxplot ###I'm getting the statistics here statplot <- broom::tidy(t.test(eggmass~Line,data=data.test)) p1 <- ggplot(data.test,aes(x=Line, y=eggmass)) + geom_boxplot() + geom_jitter(height=0, width=0.25) + annotate("text", x=1.5, y=max(data.test$eggmass), label=paste("p =", signif(statplot$p.value, 2))) p1 ``` ### Save the plot (exercise) Add the code to save the plot ```{r} ``` Confirm that you now have a file on your HDD, within the folder you set as your working directory. ## A for-loop ### For-loop over t-tests (exercise) Here you can add notes to help yourself in the future. ```{r} ###Get the unique genotypes to test against Col-0 genotypes <- unique(pheno_data$Line) genotypes <- genotypes[genotypes != "Col-0"] ###this makes an empty list output <- as.list(NULL) for(i in 1:length(genotypes)){ ### We select the data from one batch ### You need to replace AAA (2 times) with a selection of a genotype data.test <- dplyr::group_by(pheno_data,screening) %>% dplyr::filter(("Col-0" %in% Line & AAA %in% Line)) %>% dplyr::ungroup() %>% dplyr::filter(Line %in% c("Col-0",AAA)) ### conduct test and print the p-value ### you can select the p-value in the t-test output with $p.value t.test(eggmass~Line,data=data.test) ### print the p-value } ``` ### For loop for plotting (exercise) Here you can add notes to help yourself in the future. ```{r} ###Get the unique genotypes to test against Col-0 genotypes <- unique(pheno_data$Line) genotypes <- genotypes[genotypes != "Col-0"] ###this makes an empty list output <- as.list(NULL) for(i in 1:length(genotypes)){ ### We select the data from one batch ### The mutate on the final line of this chunk make sure that Col-0 is always on the left. data.test <- dplyr::group_by(pheno_data,screening) %>% dplyr::filter(("Col-0" %in% Line & genotypes[i] %in% Line)) %>% dplyr::ungroup() %>% dplyr::filter(Line %in% c("Col-0",genotypes[i])) %>% dplyr::mutate(Line = factor(Line,levels=c("Col-0",genotypes[i]))) ### conduct test and clean the result with broom::tidy statplot <- broom::tidy(t.test(eggmass~Line,data=data.test)) ### Make the plot into the empty list ### here add the fancy plotting script we made before, and save its graphs into output } ``` ### Save the plots Here you can add notes to help yourself in the future. ```{r} ###One big happy pdf pdf(file="Figure_All_Col0-comparisons.pdf",width=3,height=4) for(i in 1:length(output)){ print(output[[i]]) } dev.off() ``` ### Save individual plots (exercise) Complete the code, so you can make a .png of each plot individually. ```{r} ```