in reply to
Your code does not compile, and your problem description is wrong.
Your problems have to do with converting between the returned array, and the scalar
$weight you assign it to.
Please search this site for responses to Your and your collegues VERY SIMILAR questions over the last few days, and avoid duplicate questions.
"By three methods we may learn wisdom: First, by reflection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest."