This website is a free and comprehensive guide to learn R for anyone who has the privileges of accessing the web. We hope to cater a diverse userbase for our website: - Absolute beginner - Intermediate users - Power users - Educators - Nerds and wonks ## Absolute beginner If you are new to R coding we suggest you read first four topics (Intro, Coding 101, Data Wrangling, R graphics) in their order, try some exercises, and definitely attempt to write your own code. After that, you can decide your learning path based on your interest(s). If you are into biological data analysis read the chapters on biostatistics, survival analysis, NGS data analysis. If you are an experiemntalist, attempting to use R for analysing your experimental data, we suggest you read the biostat chapter, then go through the R for the bench. If you are a modeler planning to use R for mathematical modelling we suggest you should read the chapter on systems biology, once your knowledge of R syntax is clear. If you are into bioinformatics, after the first three chapters, read the chapter on sequence analysis and the chapter dedicated to bioinformatics packages. The chapters on machine learning can be of interest to both biostat enthusiasts and bioinformaticians. Once you feel confident writing R code (which you will if you carefully go through first three chapters), we want you to design your own learning experience. Remember, like any other learning process, best way to learn R coding is by writing R code - and making new mistakes through doing experiments with your R code. Programmers call this process 'code testing' - testing is your best teacher. ## Intermediate users If you are an intermediate user, we are fairly sure you reached to our website while Googling for some part of your R code you are working on. You were not sure about some tidy syntax, or may be you were going through some confusion on different correlation coefficients available in R, before you had your coffee in the morning. Welcome!! We admit, coffee helps. We suggest you make extensive use of the website search bar on the left top of this website, just below the website logo. We have attempted to cover a lot of grounds here, there is a whole lot of contents at different layers in this website and hence quickly searching what you are looking for is a cool idea. Feel free to use code snippets from this website for your scripts. However with the risk of sounding like a grumpy old man, we would like to say this: try to remember the syntax and write the snippets in your console yourself. If you have time, maybe read the paragraph just before the code snippet which explains the syntax. We are all learners, and R is so vast that all of us should keep learning, as frequently as we can. We like to think that using `ctrl+c`, `ctrl+v` too much leads to the same fate as what happened to Gregor in Metamorphosis. Sorry, if that was dark and pedantic. But we truly believe that the capacity to write R code spontaneously is real creative bliss to experience. And Googling for code snippets takes the joy out of it. It is the kind of annoyance you feel when the chain in your bike fails again and again, and you have to stop and put it back every time. ## Power users If you are a R power user and you are here, possibly you are checking out some advanced topics. We have no suggestions for you. Look around and feel free to write to us if you think we made a mistake somewhere. We made this website because the good books on R are too costly to purchase in different parts of the world, especially in Africa, South Asia, parts of Eastern Europe and South America. However, most families in the later places have access to at least one smart phone, if not to laptops or desktops. An R book printed in North America is almost at the same price range with those of smart phones in the developing nations. Having a smart phone is an absolute necessity these days in a family almost anywhere in the world, but a book on R is not. The reason we are saying these things here is because any help with this advertisement-free website will be deeply appreciated. And we *only* solicit academic help, such us telling us what we could have done better and where the text or the code requires corrections. Needless to say, we, the authors of R4bio, are just humble learners of R, and we are sure we are not doing everything right. ## Educators If you are an educator and you are here, you are possibly looking for materials for your students. We are so glad you are here. All our efforts will be meaningful if you use it for your class. Both of us are educators. While one of us have experience of class room teaching of computer coding for several decades at the university level. But good teaching is always tricky, especially when we try to teach R, which keeps transforming itself every five years. The webpages here are written as a textbook on R for the novice. We assume no prior knowledge of any kind. It can suitable to teach high schoolers. But we believe, it is most suitable for college and university students, and of course, for PhD course works in biological sciences. But again, no prior knowledge is assumed. And hence it should not be impossible for even pre-high schoolers to learn from this website. Being absolutely free of any advertisements should contribute to undistracted learning for your students. Every chapter has dedicated exercises with hundreds of questions of different types: multiple choice, descriptive and analytical. We hope these questions will be useful for you to organize quiz sessions, and set exam questions. We are determined to keep this website live, updated and noncommercial for the next several decades. Hence, if you use this website for teaching your students, they will know the text and the code snippets well and they can come back here for reference, whenever they need to write R code in their careers. If you have any feed back for us, and most importantly, if your students have feed backs for us, kindly let us know. We shall be grateful for your suggestions and for allowing us to learn from your experience. ## Nerds and Wonks If you like our material, just share it with other R nerds. And also share the sheer joy of building something with our own code with a fellow nerd (yes, we proudly consider ourselves as permanent members of this category). Try to share the joy of R coding especially to a budding programming wonk. That's all from us! Happy R coding!