0 votes
in SoSci Survey (English) by s170358 (110 points)

Ton run a conjoint experiment in socsi, I follow this guide by nora kirkizh (https://github.com/norakirkizh/conjoint-sosci) which used this software by Anton Strezhnev (https://github.com/astrezhnev/conjointsdt).
Unfortunately, when implementing these steps, I receive an error message.
Apparently, the floatval function is not permitted on socsci (any more?).

Is there any chance to activate the function for the project of mine?

Here is the full code I want to run and the respective error message.

Warnung: Die Funktion floatval() ist nicht zur Verwendung im Fragebogen freigegeben. Warnung: Der PHP-Code enthält Funktionen oder PHP-Elemente, die nicht für die Verwendung im Fragebogen freigegeben wurden. Falls Sie der Meinung sind, dass die monierten Konstrukte ungefährlich sind, setzen Sie sich bitte mit dem Administrator in Kontakt!

// Code to randomly generate conjoint profiles to send to a Qualtrics instance

// Terminology clarification: 
// Task = Set of choices presented to respondent in a single screen (i.e. pair of candidates)
// Profile = Single list of attributes in a given task (i.e. candidate)
// Attribute = Category characterized by a set of levels (i.e. education level)
// Level = Value that an attribute can take in a particular choice task (i.e. "no formal education")

// Attributes and Levels stored in a 2-dimensional Array 

// Function to generate weighted random numbers
function weighted_randomize($prob_array, $at_key)
	$prob_list = $prob_array[$at_key];
	// Create an array containing cutpoints for randomization
	$cumul_prob = array();
	$cumulative = 0.0;
	for ($i=0; $i<count($prob_list); $i++){
		$cumul_prob[$i] = $cumulative;
		$cumulative = $cumulative + floatval($prob_list[$i]);

	// Generate a uniform random floating point value between 0.0 and 1.0
	$unif_rand = mt_rand() / mt_getrandmax();

	// Figure out which integer should be returned
	$outInt = 0;
	for ($k = 0; $k < count($cumul_prob); $k++){
		if ($cumul_prob[$k] <= $unif_rand){
			$outInt = $k + 1;



$featurearray = array("Partisanship" => array("Republican","Democrat","Independent"),"Profession " => array("Business executive","Small business owner","Lawyer ","Farmer ","Legislative staffer","Teacher ","Served in the military"),"Political positions" => array("After supporters of the candidate unprovokedly intimated and physically attacked members of the other party, the candidate said in a 2020 interview: “What goes around comes around. What can you do when ordinary people are treated so badly? Honestly, I understand every American who is upset about politics and takes it to the street.”","Strongly condemned “anybody who entered the U.S. capitol on January 6th or who incited the hate and anger that led to these events”","Outspoken supporter of greater investments in US space programs","Recently argued that we should “spend our money here in the US instead of somewhere in outer space”"),"Issues and background" => array("Founder a civil society group to “defend and reform democracy at home and abroad”","Wants to eliminate the tax on corporations.","Was alleged to have used campaign funds for private purposes","Has once published a book that expressed overt sympathies for non-democratic systems in Asia for their “quick decisions and efficient execution”"));

$restrictionarray = array();

// Indicator for whether weighted randomization should be enabled or not
$weighted = 0;

// K = Number of tasks displayed to the respondent
$K = 2;

// N = Number of profiles displayed in each task
$N = 2;

// num_attributes = Number of Attributes in the Array
$num_attributes = count($featurearray);

$attrconstraintarray = array();

// Re-randomize the $featurearray

// Place the $featurearray keys into a new array
$featureArrayKeys = array();
$incr = 0;

foreach($featurearray as $attribute => $levels){	
	$featureArrayKeys[$incr] = $attribute;
	$incr = $incr + 1;

// Backup $featureArrayKeys
$featureArrayKeysBackup = $featureArrayKeys;

// If order randomization constraints exist, drop all of the non-free attributes
if (count($attrconstraintarray) != 0){
	foreach ($attrconstraintarray as $constraints){
		if (count($constraints) > 1){
			for ($p = 1; $p < count($constraints); $p++){
				if (in_array($constraints[$p], $featureArrayKeys)){
					$remkey = array_search($constraints[$p],$featureArrayKeys);
// Re-set the array key indices
$featureArrayKeys = array_values($featureArrayKeys);
// Re-randomize the $featurearray keys

// Re-insert the non-free attributes constrained by $attrconstraintarray
if (count($attrconstraintarray) != 0){
	foreach ($attrconstraintarray as $constraints){
		if (count($constraints) > 1){
			$insertloc = $constraints[0];
			if (in_array($insertloc, $featureArrayKeys)){
				$insert_block = array($insertloc);
				for ($p = 1; $p < count($constraints); $p++){
					if (in_array($constraints[$p], $featureArrayKeysBackup)){
						array_push($insert_block, $constraints[$p]);
				$begin_index = array_search($insertloc, $featureArrayKeys);
				array_splice($featureArrayKeys, $begin_index, 1, $insert_block);

// Re-generate the new $featurearray - label it $featureArrayNew

$featureArrayNew = array();
foreach($featureArrayKeys as $key){
	$featureArrayNew[$key] = $featurearray[$key];
// Initialize the array returned to the user
// Naming Convention
// Level Name: F-[task number]-[profile number]-[attribute number]
// Attribute Name: F-[task number]-[attribute number]
// Example: F-1-3-2, Returns the level corresponding to Task 1, Profile 3, Attribute 2 
// F-3-3, Returns the attribute name corresponding to Task 3, Attribute 3

$returnarray = array();

// For each task $p
for($p = 1; $p <= $K; $p++){

	// For each profile $i
	for($i = 1; $i <= $N; $i++){

		// Repeat until non-restricted profile generated
		$complete = False;

		while ($complete == False){

			// Create a count for $attributes to be incremented in the next loop
			$attr = 0;
			// Create a dictionary to hold profile's attributes
			$profile_dict = array();

			// For each attribute $attribute and level array $levels in task $p
			foreach($featureArrayNew as $attribute => $levels){	
				// Increment attribute count
				$attr = $attr + 1;

				// Create key for attribute name
				$attr_key = "F-" . (string)$p . "-" . (string)$attr;

				// Store attribute name in $returnarray
				$returnarray[$attr_key] = $attribute;

				// Get length of $levels array
				$num_levels = count($levels);

				// Randomly select one of the level indices
				if ($weighted == 1){
					$level_index = weighted_randomize($probabilityarray, $attribute) - 1;

					$level_index = mt_rand(1,$num_levels) - 1;	

				// Pull out the selected level
				$chosen_level = $levels[$level_index];
				// Store selected level in $profileDict
				$profile_dict[$attribute] = $chosen_level;

				// Create key for level in $returnarray
				$level_key = "F-" . (string)$p . "-" . (string)$i . "-" . (string)$attr;

				// Store selected level in $returnarray
				$returnarray[$level_key] = $chosen_level;


			$clear = True;
			// Cycle through restrictions to confirm/reject profile
			if(count($restrictionarray) != 0){

				foreach($restrictionarray as $restriction){
					$false = 1;
					foreach($restriction as $pair){
						if ($profile_dict[$pair[0]] == $pair[1]){
							$false = $false*1;
							$false = $false*0;
					if ($false == 1){
						$clear = False;
			$complete = $clear;


// Return the array back to Qualtrics
print  json_encode($returnarray);

1 Answer

0 votes
by SoSci Survey (308k points)

Apparently, the floatval function is not permitted on socsci

That is correct. You can simply use PHP type casting instead.

$cumulative = $cumulative + floatval($prob_list[$i]);

This is the same with type casting via (float):

$cumulative = $cumulative + (float)($prob_list[$i]);
asked Jan 3, 2022 in SoSci Survey (English) by s201771 (110 points) Several functions not permitted

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