randomly generate seating groups

readme.md

#Randomly create groups ##A tool to randomly generate seating groups

This tool will select the students from a spreadsheet, break them into their classes, and randomly assign them to groups. I created this tool to quickly generate random seating groups for my students.

createGroups

function createGroups() {
  //create a new document
  
  var date = new Date();
  var document = DocumentApp.create("Seating Groups " + date.toDateString()).getBody();

  //declare the object classList filled with an array for each class
  var classList = {};
  
  var newGroups = {};
  
  //set the number of groups to create (later change this to a function parameter)
  var numGroups = 6;
  
  
  //range of cells to get the students names from
  var nameRange = SpreadsheetApp.getActiveSheet().getRange(2, 2, 86, 4).getValues();
  var classNames = [];
  
  nameRange.map(function(each) {
    if(classNames.indexOf(each[2]) === -1) {
      classNames.push(each[2]);
    }
  });
  
  //add classes to object and shuffle the classes
  for(var i = 0; i < classNames.length; i++) {
    var currentClass = nameRange.filter(function(each) { return each[2] === classNames[i]; });
    classList[classNames[i]] = shuffle(currentClass);
  }
  
  //break classes into even groups
  for(var key in classList) {
    var groupMax = Math.ceil(classList[key].length / numGroups);
    var groupExtra = classList[key].length % numGroups;
    
    newGroups[key] = {};
    
    for(i = 1; i <= numGroups; i++) {
      
      newGroups[key]["Group "+i] = classList[key].splice(0, groupMax);
      
      if(--groupExtra === 0) {
        groupMax--;
      }
      
    }

    document.appendParagraph(key).setHeading(DocumentApp.ParagraphHeading.HEADING1);
    
    for(var groupKey in newGroups[key]) {
      document.appendParagraph(groupKey).setHeading(DocumentApp.ParagraphHeading.NORMAL);
      for(var i = 0; i < newGroups[key][groupKey].length; i++) {
        document.appendParagraph(newGroups[key][groupKey][i][0] + " " + newGroups[key][groupKey][i][1]);
      }
      document.appendHorizontalRule();
    }
    document.appendPageBreak();
  }

}

shuffle

function shuffle(array) {
  var currentIndex = array.length, temporaryValue, randomIndex ;

  // While there remain elements to shuffle...
  while (0 !== currentIndex) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // And swap it with the current element.
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}