For this project, we developed three different kinds of data visualization about Pokemon demographics: Types of Pokemon, Combat Statistics, and Winning Rates for Different Types of Pokemon.
We started off by brainstorming what data we would be using and then drew sketches illustrating what each part of data visualization looks like.
Data preprocessing
Then we divided the work, each doing one type of visualization. In this case, I was responsible for doing the first part, Types of Pokemon. We each preprocessed the datasets we obtained from Kaggle.com: Pokemon- Weedle's Cave and Pokémon for Data Mining and Machine Learning. 
For the first part of visualization, I would like to show the types of Pokemon and how many Pokemons are in each type, so I took the variables of Pokemon “Type_1” and “Type_2” from the Pokémon for Data Mining and Machine Learning dataset file and counted how many Pokemon in each type and generated a Count variable in order to create a new csv file called “pokemontype.csv.”
Data visualization
For the first part of visualization, Types of Pokemon, I set a svg canvas with 960 px in width and 500 px in height. Then I mapped the data of Type of Pokemon and the number of each Type to radial axes. In this case, I used a linear scale, setting the domain from 0 to the max number of “Count” variable in the dataset times 1.5, and the range from 0 to 2 times Math.PI. Then I defined keys to hold the data from variable “Type” and set the number of arcs to the length of keys. In addition, I defined a variable called labelPadding and set it to -5 in order to align the texts naming all the Pokemon types to the left of the semicircle, and a variable called numberPadding and set it to -40 in order to align the texts of number of each Pokemon type to the left of texts of each type’s name. As for the colors of this part of visualization, we defined a variable called color and gave it a range of colors we chose by ourselves to represent each type of Pokemon. In order to make the chart more visually enjoyable, a linear gradient effect to the color of each type of pokemon is added, where the color starts very light and changes gradually to darker around the middle of the arc and then faded towards the end of the arc.