custom function to create a numerical average from text fields in google sheets

AVGCOMPLETES.gs

function AVGCOMPLETES(arr) {
  //declare the array that will be used to get the average
  //push 100 to the array if the field is 'complete' and 0 to the array if the field is 'incomplete'
  var averageArray = [];
  for(i = 0; i < arr[0].length; i++) { 
    if(typeof arr[0][i] === 'string') { 
      if(arr[0][i].toLowerCase() === 'complete') { 
        averageArray.push(100); 
      } else if(arr[0][i].toLowerCase() === 'incomplete') { 
        averageArray.push(50); 
      } else if(arr[0][i].toLowerCase() === 'missing') { 
        averageArray.push(0); 
      } 
    } else { 
      averageArray.push(arr[0][i]); 
    } 
  } 
  //average all the values in the array 
  var length = averageArray.length; 
  var average = averageArray.reduce(function(first, second) {return first + second;}) / length; 
  
  //return the rounded average 
  return Math.round(average); 
}