Haskell Data Analysis Cookbook

Plotting a pie chart using Google's Chart API

The Google Chart API provides a very elegant-looking pie chart interface. We can generate images of well-designed pie charts by feeding our input and labels properly, as described in this recipe.

Getting ready

Install the GoogleChart package as follows:

$ cabal install hs-gchart

Create a file called input.txt with numbers inserted line by line as follows:

$ cat input.txt 
2
5
3
7
4
1
19
18
17
14
15
16

How to do it…

1. Import the Google Chart API library as follows:

   import Graphics.Google.Chart

2. Gather the input from the text file and parse it as a list of integers, as shown in the following code snippet:

   main = do
     rawInput <- readFile "input.txt"
     let nums = map (read :: String -> Int) (lines rawInput)

3. Print out ...