Course: Data-Driven Management and Policy

Prof. José Manuel Magallanes, PhD


Session 4 LAB: Working with Data Frames

Lab Instructions

Part 1:

You saw this code in the session:

# one input, and several output in simple data structure:
factors=function(number){
    # empty vector that will collect output
    vectorOfAnswers=c()
    
    # for every value in the sequence...
    for (i in 1:number){
        
        #if the remainder of 'number'/'i' equals zero...
        if ((number %% i) == 0){ 
            
            # ...add 'i' to the vector of factors!
            vectorOfAnswers=c(vectorOfAnswers,i)
    }
  }
  return (vectorOfAnswers) # returning  the vector
}

This function accepted an integer number and returned its factors. Please answer these questions:

  1. For any number N, how many times does the for section is executed to compute the factos of N?

  2. Make a change in the code to reduce the times the for section is executed.

Part 2:

Open the file demo_hdi, it is a csv file in the folder you downloaded. Then,

  • Get the max value of human development index for each type of democracy.

You should get something like this:

  • Use those values to select the rows whose hdi matches one of those.

You should get something like this:

  • Turn that wide format into a long format.

You should get something like this: