README.md

#Grade curving with Google Sheets

Make a copy of a demo grading sheet here: Demo Grade Sheet Showing some methods to curve a grade based on this original blog post I have used to get more examples of how to curve grades

Code.gs

/**
 * Return, rewrite, regrade
 *
 * @param {number} The original grade
 * @param {number} The re-graded assignment
 * @param {number} The percentage of the regraded assignment to count
 * @return The curved grade
 * @customfunction
 */
function REGRADEDCURVE(original, newGrade, percentage) {
  var regraded = original + (newGrade - original) * (percentage * .01);
  
  return regraded;
  
}

/**
 * Flat curve
 *
 * @param {number} Original grade
 * @param {number} Number to add to grade
 * @return The curved grade
 * @customfunction
 */
function FLATCURVE(original, flat) {
  return original + flat;
}

/**
 * High Grade to a 100%
 *
 * @param {number} Highest grade
 * @param {number} Grade to be curved
 * @return The curved grades
 * @customfunction
 */
function HIGHCURVE(highGrade, grade) {
  
  return Math.round((100 * grade) / highGrade);
  
}

/**
 * Linear Scale
 *
 * @param {number} The AVERAGE of the grades
 * @param {number} The DESIRED AVERAGE of the grades
 * @param {number} The LOWEST or HIGHEST grade
 * @param {number} The DESIRED LOW or HIGH grade
 * @param {number} The grade to be curved
 * @return The curved grade
 * @customfunction
 */
function LINEARCURVE(x0, y0, x1, y1, grade) {
  
  return Math.round(y0 + ((y1 - y0) / (x1 - x0)) * (grade - x0));
  
}

/**
 * Root Curve
 *
 * @param {number} The grade to curve
 * @return The curved grade
 * @customfunction
 */
function ROOTCURVE(grade) {

  return Math.round(Math.pow((100 * Math.pow(grade, 2)), 1/3));
  
}

/**
 * Bell Curve
 *
 * @param {number} The grade to curve
 * @customfunction
 */
function BELLCURVE(grade) {
  return 'Please do not use this curve!';
}