Anonymous bulletin board for Data Analysis with Python class by Arko B

Good afternoon, Arko,Thanks for your kind help to start this course for us in the postdoc training program. I have got very strong interest in using R and other related software for data analyses. Based on my previous study experience, I would suggest that our trainees could repeatedly practice the commands which you have already well prepared for us, step by step before classes. Instead of repeating your instructions in class, I would like to learn more about the following information: 1. Why and when will we use these commands, and also, how to generate these commands? 2. How to organize and prepare the original databases, so they could be recognized and analyzed easily by R? Thanks a lot!

2019-01-28 19:34:48 UTC

Reply: Thank you for your feedback!
1. The commands are pre-built, some of them in the "base" R, others are packaged in the form of libraries (Remember we used ggplot2 in class, that is a package)! I will touch on this in the next class. The fun part is that you can build your own library and upload it, and people all over the world can download and use it.
2. Any csv or excel file can be opened in R! Think of it as a kind of spreadsheet tool like excel, but you can have your own column names to write formulas (unlike excel), and the plots are fantastic. You can also do a huge amount of statistical analysis using hundreds of packages (without going into too much details about how the calculations are done under the hood). Moreover, you have absolute control over how you make your plots!
See you in class (whoever you are)!
~ Arko

Hi Arko,

2019-06-11 16:10:24 UTC

I have one query
I have one vector having 7 values. I want to remove values less than 5 from this vector. I tried but failed. Could you please help me
myvector <- c(1,2,4,8,12,5,9)

Reply: First you will need to find the indices of the elements which are greater than or equal to 5. Then use these indices to extract only those values which are greater than or equal to 5. Here is the solution:

# geq5Indices is a logical vector of
# indices where the elements are >= 5
geq5Indices <- myvector >= 5
# newVector contains only values >= 5
newVector <- myvector[geq5Indices]

~ Arko

Practice Problems

2020-02-14 01:02:01 UTC

Hi Arko,
If it's not too much work,
could you post some practice "homework" using what we have learned so far. Then, maybe after a week you could post an answer key for us to check?

Good idea! I will post one today.
We will also start working on projects, I will have the team information out today (3/5/2020).
~ Arko