data co-occurrence in JSON dataset

Question

I'm having trouble extracting JSON information. My JSON file contains 100 chapters of a novel. Each chapter contains a number of characters found in the chapter.

For instance:

{"ONE": ["PERSON A", "PERSON B", "PERSON C", "PERSON D", "PERSON A"],
"TWO": ["PERSON A", "PERSON D", "PERSON F", "PERSON G", "PERSON H"],
"THREE": ["PERSON F", "PERSON D", "PERSON A", "PERSON A", "PERSON A"]
... "ONE HUNDRED": ["PERSON B", "PERSON A"]
}

My goal is to design a method to extract how many times two characters co-occurred in the whole book, and two characters can only co-occur once in a chapter. eg, within 100 chapters, I want to know how many times PERSON A and PERSON B co-occurred.

I have two methods in mind, A. Use JSON PATH and filter out the dataset (where PERSON A and B co-occurred), and calculate the number of chapters they co-occurred. (I don't know what to query either :P ) B. Although I'm not really good with JAVASCRIPT. My idea is to define an integer, and then run for loops in every chapter of the JSON file.

I wonder if you guys could share your knowledge with me on this! Thanks!

Answer 1

Here's a function where you can specify if you want the count or an array of chapters

Here is the function broken down

const cooccur = (people, rettype) => {
  let result = Object.keys(
  // the final result will be an array of object keys
     Object.fromEntries(Object.entries(chapters)
     // but to iterate your object, we need to first convert it into an array with Object.entries
     // then with that result, convert it back into an object with Object.fromEntries
        .filter(c => people.filter(r => c[1].indexOf(r) > -1).length === people.length)));
         // this double filter will run through each chapter and filter it based on the second filter's result
         // the second filter takes our people array and finds how many total occurences of both people in a given chapter
         // if the total number of occurences equals the number of people we're searching for, it's a match
  return rettype === 'count' ? result.length : result;
}

let chapters = {
  "ONE": ["PERSON A", "PERSON B", "PERSON C", "PERSON D", "PERSON A"],
  "TWO": ["PERSON A", "PERSON D", "PERSON F", "PERSON G", "PERSON H"],
  "THREE": ["PERSON F", "PERSON D", "PERSON A", "PERSON A", "PERSON A"],
  "ONE HUNDRED": ["PERSON B", "PERSON A"]
}

const cooccur = (people, rettype) => {
  let result = Object.keys(Object.fromEntries(Object.entries(chapters).filter(c => people.filter(r => c[1].indexOf(r) > -1).length === people.length)));
  return rettype === 'count' ? result.length : result;
}

console.log('number of occurences:', cooccur(["PERSON A", "PERSON B"], 'count'));
console.log('occurence chapters:', cooccur(["PERSON A", "PERSON B"], 'chapters'));