Calculated field returns undefined index

Question

I'm trying to average all of the fivestar ratings I have for a node using a computed field. But i'm struggling to simply access the other fields using entity!

In the body of the node, this works fine:

$test1 = $node->field_ae_stimclasswrk[und][0]['average'];

In the computed field area, this doesn't work:

$entity_field[0]['value'] = $entity->field_ae_stimclasswrk[$entity->language][und][0]['average'];

Instead, when I save the node, I get this index error:

Notice: Undefined index: und in eval() (line 2 of...

It must be something syntax, but I'm completely out of ideas.

Here is the field info:

    [field_ae_stimclasswrk] => Array
        (
            [und] => Array
                (
                    [0] => Array
                        (
                            [user] => 80
                            [average] => 80
                            [count] => 1
                        )

                )

        )

Answer 1

$entity->language is the same as und so try using:

$entity_field[0]['value'] = $entity->field_ae_stimclasswrk[$entity->language][0]['average'];