It sounds to me like you need to create a HoA (Hash of Arrays). However, creating a datastructure 3 levels deep with a hash of array of arrays (HoAoA) may not be what you want. Without actually showing us some sample data, it is difficult for us to determine what kind of data structure you need and how to define/initialize it. You may want to look at planetscape's Re: How can I visualize my complex data structure? to get a better idea of what it is you want and how to better organize. This should also give you an idea of how to access data within the data structure.