function form_radio($name, $value=NULL, $checked=NULL, $attributes=NULL, $additional_code=NULL) {

$extra = '';

if (!isset($value)) {
$value = '1';
}

if (!isset($checked)) {
$checked = false;
}

if (isset($attributes)) {
$extra = get_attributes_str($attributes);
}

if ($checked == true) {
$extra.= ' checked';
}

if (isset($additional_code)) {
$extra.= ' '.$additional_code;
}

$html = '';
return $html;
}

echo form_open_upload($form_location);
echo form_radio("name1","value1");
echo form_radio("name1","value2");
echo form_radio("name1","value3");
echo form_submit('submit', 'Submit');
echo form_close();

and

//create.php view file
<h1 style="color: #8258FA"><?= "Survey Form" ?></h1>
<?= validation_errors('<p class="error">', '</p>') ?>
<div class="card">
<div class="card-heading">
Survey Form
</div>
<div class="card-body">
<?php
flashdata();
echo form_open($form_location);

echo form_label('<b>01. Question 1</b>');
echo '<div>Response: ';
echo form_radio('ans01', 1, $checked01=$ans01, $attributes=NULL, '<span> Unhappy </span');
echo form_radio('ans01', 2, $checked01=$ans01, $attributes=NULL, '<span> Fine </span');
echo form_radio('ans01', 3, $checked01=$ans01, $attributes=NULL, '<span> Happy </span');
echo '</div>';

echo form_label('<b>02. Question 2</b>');
echo '<div>Response: ';
echo form_radio('ans02', 1, $checked02=$ans02, $attributes=NULL, '<span> Unhappy </span');
echo form_radio('ans02', 2, $checked02=$ans02, $attributes=NULL, '<span> Fine </span');
echo form_radio('ans02', 3, $checked02=$ans02, $attributes=NULL, '<span> Happy </span');
echo '</div>';

echo form_submit('submit', 'Submit');
echo anchor('survey/main_survey', 'Cancel', array('class' => 'button alt')); //$cancel_url Survey/main_survey
echo form_close();
?>
</div>
</div>

==============================================

//Survey.php controller file
<?php
class Survey extends Trongate {

function create() {

$data = $this->_get_data_from_post();
$data['form_location'] = str_replace('/create', '/submit', current_url());
$data['view_file'] = 'create';
$this->template('admin', $data);

}

function _get_data_from_post() {

$data['ans01'] = post('ans01', true);
$data['ans02'] = post('ans02', true);

$data['checked01'] = post('checked01', true);
$data['checked02'] = post('checked02', true);


return $data;
}


function submit() { //submit

$submit = post('submit', true);


if ($submit == 'Submit') {

$this->validation_helper->set_rules('ans01', 'Question 01 response', 'required');
$this->validation_helper->set_rules('ans02', 'Question 02 response', 'required');


$result = $this->validation_helper->run();


if ($result == true) {

$data = $this->_get_data_from_post();

//update remote database

redirect('survey/create');

} else {
//form submission error
$this->create();
}
}
}
}

<div class="container">
<h1>Online Survey</h1>
<p>Please fill out the form below and then hit 'Submit'.</p>
<?php
echo form_open('questions/submit', array('class' => 'highlight-errors'));
echo form_label('First Name:');
echo validation_errors('first_name');
echo form_input('first_name', $first_name, array('placeholder' => 'Enter your first name here...'));

echo form_label('Last Name:');
echo validation_errors('last_name');
echo form_input('last_name', $last_name, array('placeholder' => 'Enter your last name here...'));

echo form_label('Email Address:');
echo validation_errors('email_address');
echo form_email('email_address', $email_address, array('placeholder' => 'Enter your email address here...'));

echo '<h3>Question 1</h3>';
echo '<p>How do you feel today?</p>';
echo validation_errors('answer1');
echo '<div>';
echo '<p>';
$selected1 = ($answer1 == 'Happy') ? 1 : 0;
echo form_radio('answer1', 'Happy', $selected1);
echo ' Happy';
echo '</p>';

echo '<p>';
$selected2 = ($answer1 == 'Happy') ? 1 : 0;
echo form_radio('answer1', 'Angry', $selected2);
echo ' Angry';
echo '</p>';

echo '<p>';
$selected3 = ($answer1 == 'Sad') ? 1 : 0;
echo form_radio('answer1', 'Sad', $selected3);
echo ' Sad';
echo '</p>';
echo '</div>';
echo form_submit('submit', 'Submit');
echo form_close();
?></div>

<?php
class Questions extends Trongate {

function create() {
$data = $this->_get_data_from_post();
$data['view_file'] = 'create';
$this->template('admin', $data);
}

function submit() {
$this->validation_helper->set_rules('first_name', 'first name', 'required');
$this->validation_helper->set_rules('last_name', 'last name', 'required');
$this->validation_helper->set_rules('email_address', 'email address', 'required|valid_email');
$this->validation_helper->set_rules('answer1', 'first question response', 'required');

$result = $this->validation_helper->run();

if ($result == true) {
$data = $this->_get_data_from_post();
//$this->model->insert($data);
echo 'well done';
} else {
$this->create();
}
}

function _get_data_from_post() {
$data['first_name'] = post('first_name', true);
$data['last_name'] = post('last_name', true);
$data['email_address'] = post('email_address', true);
$data['answer1'] = post('answer1', true);
return $data;
}

}