Please post a small self contained sample with data that demonstrates the problem with the description of what you expected and what you get. Not a link, but a copy of actual code that demonstrates the actual problem using actual data on your actual node.

Links to sites outside PerlMonks tend to be transient. Code posted in your node will last as long as the node does. PerlMonks nodes are often used by people and provide value long after the OP's problem has become a dusty memory. Please be considerate to future monks by providing a complete succinct context in your node.