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blog:2020-03-16:covid-19_spread [2020/03/23 08:52] va7fiblog:2020-03-16:covid-19_spread [2020/08/07 13:03] – external edit 127.0.0.1
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 <hidden Show Formulae> <hidden Show Formulae>
 The formulae for the exponential curves are: The formulae for the exponential curves are:
-  * $N = 24.5 \times 2^{(\frac{t}{4.1})}$ for the green line (where //t// is the number of days since March 2) +  * \$N = 24.5 \times 2^{(\frac{t}{4.1})}\$ for the green line (where //t// is the number of days since March 2) 
-  * $N = 93.1 \times 2^{(\frac{t}{2.7})}$ for the blue line (where //t// is the number of days since March 10)+  * \$N = 93.1 \times 2^{(\frac{t}{2.7})}\$ for the blue line (where //t// is the number of days since March 10)
 </hidden> </hidden>
 \\ \\
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 But doing the right things can change that future.  In reality, the spread of the infection follows more of a [[wp>Logistic_function |Logistic Function]].  At the beginning, it looks like an exponential, but then it flattens out.  This is what the news keeps referring to when they say that social distancing and proper hand washing can help "flattening the curve" more quickly. But doing the right things can change that future.  In reality, the spread of the infection follows more of a [[wp>Logistic_function |Logistic Function]].  At the beginning, it looks like an exponential, but then it flattens out.  This is what the news keeps referring to when they say that social distancing and proper hand washing can help "flattening the curve" more quickly.
 {{ :blog:2020-03-16:480px-logistic-curve.svg.png }} {{ :blog:2020-03-16:480px-logistic-curve.svg.png }}
-The real question is how soon will we reach that middle point, and at what height.+The real question is how soon we will reach that middle point, and at what height.
  
 Here's a good video that explains this sort of math and why being able to think in exponential term is important for non-linear systems such as this one. Here's a good video that explains this sort of math and why being able to think in exponential term is important for non-linear systems such as this one.
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 The equation for "Model 3" is: The equation for "Model 3" is:
 <WRAP centeralign> <WRAP centeralign>
-$$N = \frac{2000}{1 + e^{-0.32(t - 21.1)}}$$+\$$N = \frac{2000}{1 + e^{-0.32(t - 21.1)}}\$$
 </WRAP> </WRAP>
  
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 Its equation is: Its equation is:
 <WRAP centeralign> <WRAP centeralign>
-$$N = \frac{20000}{1 + e^{-0.24(t - 32)}}$$+\$$N = \frac{20000}{1 + e^{-0.24(t - 32)}}\$$
 </WRAP> </WRAP>
  
blog/2020-03-16/covid-19_spread.txt · Last modified: 2020/10/13 17:48 by va7fi