Experimental Design Random Name Picker

namepicker.js

var fs = require('fs');
var data = fs.readFileSync('listofnames.txt','utf8').toString().split("\n");
var mainset = []; //Random group of 60 students
var subsetOne = []; //Random group of a subset of 30 / 60 students
var subsetTwo = []; //Random group of a subset of 30 / 60 students
var indicesSetOne = [];
var indicesSetTwo = [];
var indicesSetThree = [];

//Random function with arg max number
function r(max){
	return Math.floor(Math.random() * (max - 0) + 0);
}

/* Get 60 random numbers in between 0 and 74) */
while(indicesSetOne.length < 60){
	var num = r(75);
	if(indicesSetOne.indexOf(num) == -1){
		indicesSetOne.push(num);
	}
}

/* Slurp names into mainset  */
for(var i in indicesSetOne){
	mainset.push(data[indicesSetOne[i]]);
}

/* Get 30 random numbers in between 0 and 59 */
while(indicesSetTwo.length < 30) {
	var num = r(60);
	if(indicesSetTwo.indexOf(num) == -1){
		indicesSetTwo.push(num);
	}
}

/* Slurp names into subsetOne */
for(var i in indicesSetTwo){
	subsetOne.push(data[indicesSetTwo[i]]);
}

/* Get 30 random numbers in between 0 and 59
	but make sure they haven't already been chosen
*/
while (indicesSetThree.length < 30){
	var num = r(60);
	if(indicesSetThree.indexOf(num) == -1){
		if(indicesSetTwo.indexOf(num) == -1){
			indicesSetThree.push(num);
		}
	}
}

/* Slurp names into subsetTWo */
for (var i in indicesSetThree){
	subsetTwo.push(data[indicesSetThree[i]]);
}

/*  Write output file */
fs.writeFile('output.txt',"===First Group of 30==="+"\n"+subsetOne+"\n"+"===Second Group of 30==="+"\n"+subsetTwo);