How to Calculate Confidence Intervals for Crosstabs with Categorical Questions

// Choose which stats to replace.
var upper_statistic_to_replace;
var lower_statistic_to_replace;
// Categorical results
if (table.availableStatistics.indexOf("Column %") > -1) {
   var upper_statistic_to_replace = "Index";
   var lower_statistic_to_replace = "Missing n";
} else {
   table.suppressOutput('Confidence intervals not computed - it only applies to tables containing Column % in the Statistics - Cells');
   form.ruleNotApplicable('it only applies to tables containing Column % in the Statistics - Cells');
}

if (["Pick One", "Pick Any"].indexOf(table.blueQuestion.questionType) == -1 || ["Pick One", "Pick Any"].indexOf(table.brownQuestion.questionType) == -1){
   table.suppressOutput('Confidence intervals not computed - the table should have a Pick One or Pick Any question selected in the Blue and Brown drop-down menus.');
   form.ruleNotApplicable('the table should have a Pick One or Pick Any question selected in the Blue and Brown drop-down menus.');
}

// Set up controls for user input.
form.setSummary('Calculate confidence intervals on crosstabs with percentages'); 
form.setHeading('Calculate confidence intervals on crosstabs with percentages');

var label = form.newLabel('Significance level:');
var p_level = form.newNumericUpDown('Lower');
p_level.setIncrement(0.01);
p_level.setDefault(0.05);
p_level.setMaximum(1);
p_level.setMinimum(0);
form.setInputControls([label, p_level]);

var p_cutoff = p_level.getValue();

// Get relevant table stats
var n = table.get("n");
var col_n = table.get("Column n");
var col_percent = table.get("Column %");
var col_se = table.get("Column Standard Error");
var upper_values = table.get(upper_statistic_to_replace);
var lower_values = table.get(lower_statistic_to_replace);
var isWeight = table.weight != null;

// Do the calculations
for (var row = 0; row < table.numberRows; row++) {
 for (var col = 0; col < table.numberColumns; col++) {
  var z = jStat.normal.inv(p_cutoff/2,0,1);

  if (isWeight) {
   var increment = z*col_se[row][col]*100;
   lower_values[row][col] = col_percent[row][col] + increment;
   upper_values[row][col] = col_percent[row][col] - increment;
  } else { 
   var calc1 = col_n[row][col] + Math.pow(z,2);
   var calc2 = (n[row][col] + Math.pow(z,2)/2)/calc1;
   var calc3 = Math.sqrt(calc2*(1-calc2)/calc1);
   var increment = z*calc3;
   lower_values[row][col] = (calc2 + increment)*100;
   upper_values[row][col] = (calc2 - increment)*100;
  }

 } 
}

table.set(lower_statistic_to_replace, lower_values);
table.set(upper_statistic_to_replace, upper_values);
form.setTranslation("Index", "Upper Confidence Interval");
form.setTranslation("Missing n", "Lower Confidence Interval");