Extend current work to capture R-effective which help model trends, causal anal

[rgsachin]

Hi @aatishb , minute physics and team, Nice work. I've minor requirement rather than a issue. It'd be really helpful to study the trend of R-effective, to gauge how well a country is managing the spread.

1. This can be achieved by having the ratio of rolling average of the new cases and the rolling average of active cases on the x-axis and time on the y-axis. Since it is a ratio is does away with population depended factors which are country specific.
2. Another addition can be rate of change of above said ratio.

This can help do:

1. Forecasting models
2. Causal analysis by factorizing a country by attributes (such as testing & treatment protocols, testing rate, etc.,. which can help identify what works, what doesn't in real time)
   3, Also help in SRI simulation.

John Hopkins provide the # of recovered, which you can be used to get the active # of cases.

Thanks in advance for PR.

[leander-j]

The option to select active instead of total cases as a reference is getting more relevant every day, since now that we are past the first wave and exponential rise, total cases are dominated by deaths and recoveries instead of active cases.

This is exactly were we need data about the effective reproduction to determine the current spread!

Thanks in advance!