Page for dowloading data animation

Nature (2001) 414: 716-723

Dowload quicktime movie [fli-format][avi-format]

click here to download the Quicktime plugin >>

Structure of the movie frame
The movie shows the dynamics of measles in England and Wales during the period 1955-1965.  The data are from the Registrar General's weekly notifications of measles in 954 urban locations; the movie plots a frame every 2 weeks.

The upper left quadrant shows observed measles dynamics,  using colour coding for the logarithm of the number of reported infected cases (all data are scaled on (0-1) before plotting).  Zero case reports are shown as white circles and circle size is proportional to {population size}^0.2. The movie captures the overall synchonised biennial 'pulse' of measles epidemics, superimposed on the seasonal swing of infection. There are also more irregular epidemics in smaller places and many other interesting patterns, for example distinctive behaviour in many coastal towns.

The observed data also show travelling waves of measles, moving away from large centres such as London.  These are revealed more clearly in the upper right quadrant, which shows the smoothed major epidemic cycles, filtered using wavelets in a window of 1.75 to 3 years.  As discussed in the paper, the filtered series reveal dramatic waves of measles, moving away from large centres, especially London and the North West conurbation.  The lower left quadrant shows the phase difference from London of these filtered series (see the paper for more details).  The arrows and the colour of the arrows are indicators of the phase difference, as shown on the circular key (green denotes a zero phase difference from London, blue denotes a lag and yellow a lead).  These give a more stable picture of the phase relationships -- notably, the wave moving away from London and a relatively early wave from the North West.  Finally, the lower right quadrant plots a moving time bar against the London and Manchester series.