Multi-scale spatial patterns of H1N1 influenza occurrence in the US. Each of the spatial pattern W discovered from NMF can examine how the flu spread throughout the US (left hand panels). The nation wide panels depict how W1 pattern is widespread throughout the US followed by progressively moving down south (W4 ). The spatial pattern W5 depicts flu prevalence only within large metropolitan areas and southern Florida. One can focus further into state-wide patterns (middle panel) and examine how ILI-patterns affect the state of Tennessee and towards specific metropolitan areas (e.g., Memphis in Tennessee, right most panels) and capture minor variations in the ILI-patterns according to different zip-codes. These differences also allow one to identify bridge regions (highlighted by red and magenta circles) that show more than two ILI-patterns in the same zip code. These analyses can be further extended out towards the state and nation-wide areas.