Original

Original Visualisation:


Source:Stock Performance of the S&P 500 in 2018 by Steven Bernard, 2018


Objective

The objective of the original data visualization is to measure the companies stock performances such as percentage of share price change and their corresponding Market Capitalization as listed in S&P 500 in order for business people to carry out their trades accordingly and make informed financial decisions. As the visualisation depicts the percentage of share price change and market cap for the year 2018, many people based on the current statistics for that year would want to finalise their long or short positions accordingly for next year which is 2019. This original visualization was published in Financial times which basically targets the audience who are mainly involved or interested in business and financial circles such as wall street traders, company executives, Businessman and anyone who has invested his/her money in the stock markets.

Main issues associated with the above visualisation are as follows:

  • The visualisation is deceptive because it fails to answer the practical question of discerning the share price of a company which is of vital importance because the business people want the share price change information to be accurate to minimum 2 decimal points in order to make important financial decisions. Due to the various sizes of each data point, the audience is not able to figure out the actual share price percentage change. For instance, the company Apple has a data point between -20% and 0% but the actual share price percentage change is illegible from the visualisation. Similarly the Alphabet company has its data point on either sizes of the mark zero but the actual share price percentage is not clear.

  • Deceptive data and method is used to visualise the companies Market Capitalisation. The market capitalisation of an individual company is shown by the size of the data point and the reason its deceptive because firstly the companies such as Apple, Alphabet, Amazon and Microsft have almost same size of data point but, from the data, as taken in 2018 as per visalisation, their market capitalisation are different. Secondly, the market cap in the original visualisation represents the current cap at the end of 2018 year rather than change in market cap during the year 2018.

  • The colour used to display the visualisation is bright red. Because of this bright red colour choice, it can impair the ability of any person who suffers from Red colour blindness. In the process, there’s every possibility that the person with this type of colour blindness might misread the visualisation and come to a wrong conclusion.

Reference

Code

The following code was used to fix the issues identified in the original.

library(ggplot2)
library(readr)
library(dplyr)
library(tidyr)

# Data Preprocessing code
stock <- read_csv("C:/Users/Mohan/Desktop/RMIT Coursework/Semester 2/Data Visualization (MATH2270)/Assignment 2/Stock_Performance_2018.csv")
stock_change <- gather(stock,"Stock_Indicator","Stock_percent_change",c(4,7))
stock_final_data <- stock_change %>% select(Company,Stock_Indicator,Stock_percent_change)
stock_final_data$Company <- as.factor(stock_final_data$Company)
stock_final_data$Stock_Indicator <- as.factor(stock_final_data$Stock_Indicator)

# Visulisation recreation code

p <- ggplot(data = stock_final_data,aes(x = reorder(Company,-Stock_percent_change),y = Stock_percent_change)) 

p1 <- p + ylim(c(-210,50)) + 
  geom_bar(aes(fill = Company), stat = "identity") +
  facet_wrap(stock_final_data$Stock_Indicator,scale = "free_y",ncol = 1)+
  theme(axis.text.x=element_text(angle=45,hjust=1),legend.position = "none")

p2 <- p1 + geom_text(aes(label=paste(Stock_percent_change,"%")), 
                vjust=-0.6,size = 3,check_overlap = TRUE,position = position_dodge(0.1),fontface = "bold") +
  labs(title = "Share Price And Market Cap Percentage Change in year 2018 \n",
       y = "Percentage Change",
       x = "Companies listed in S&P 500")

```

Data Reference

Reconstruction

The plot below fixes the 3 main issues as listed in objective tab.