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AllenDowney / ThinkBayes2

Text and code for the forthcoming second edition of Think Bayes, by Allen Downey.
http://allendowney.github.io/ThinkBayes2/
MIT License
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Chapter 10 Solutions - Definition / Implementation mismatch for the logistic #49

Closed EricRobertCampbell closed 2 years ago

EricRobertCampbell commented 2 years ago

In the final exercise for Chapter 10, there is a slight mismatch between the definition of the 3-parameter logistic function and its implementation. In the definition, we see that the parameter a is multiplying the other term in the exponent of the exponential.

original

However, in the implementation in the next cell, we see that the variable a is dividing the rest of the terms (in the assignment to x).

original code

The Wikipedia link also uses the convention of having the parameter a multiply the terms. I believe that the easiest solution would be to change the value of a to 1/100 and change it to multiplication in the definition of x.

AllenDowney commented 2 years ago

Got it. Will fix. Thanks!